(B @ D U')        // EO on UD-axis (3/3)
@ = L2            // insert ext for +1p (1/4) 
R' L' # B R2 B2   // 2x2x2 on DBL (5/9)
(F' R2 F2)        // F2L-2c on L-U (3/12)
(R')              // all edges, leaving 4c2c (1/13)
# = [R F2 R', B2] // insert 3c comm (8-3/18)

rewrite: L' F2 R' B2 R F2 R' B' % R2 B2 R $ F2 R2 F U D' L2 B'
$ = [R' B2 R, F]   // insert 3c comm ( 8-6/20)
% = [B, R U' R' U] // insert 3c comm (10-5/25)

D' R B (F)           // EO on FB-axis (3+1/4)
(R' U D2)            // sq on R (3/7)
(L B2 U R2)          // 2x2x3 on UR (4/11)
D L2                 // F2L-1p on U-BL (2/13)
L' D2 L              // ZBLS, giving F2L on U (3-1/15)
L D2 $ L' D' L D' L' // COLL using Anti-Sune, leaving Z-Perm on D (7-1/21)
$ = [D2 L2]*3        // insert 2e2e (6-8/19)

rewrite: D' R B D L' D2 L D' L D' L' R2 U' B2 % L' D2 U' R F'
% = B2 L R' U2 R L'  // insert 3e (6-3/22)

// NOTE: solved Z-Perm in +1 :)

(F' U' L' @ B2)           // sq on R (4/4)
(R' D' R2) B'             // 2x2x3 on DR (3+1/8)
(L' U)                    // F2L-1e on R-UF (2/10)
(U' L' U L U B' U' B)     // all corners, leaving 2e2e, -1 on normal (8-3-1/14)
@ = L2 D2 R2 F L2 U2 R2 B // insert 2e2e alg (8-2/20)
============================================================
backup solution:
(D2 R' U' B)         // EO on FB-axis (4/4)
U' D B2 R' L U'      // 2x2x3 on UB (6/10)
F2 D2                // F2L-1p on B-DR (2/12)
F2 R U # F2 U' R' F2 // all edges using a conj (7/19)
# = [U' R' U, L']    // insert 3c comm (8-4/23)

(F2 D' B L2 U L B) // sub-opt 2x2x2 on UBL (7/7)
D2 R2 D R L' F L   // 2x2x3 on BL (7/14)
F' $ % R2          // all but 5c  (2/16)
$ = [F L' F' L, U] // insert 3c comm (10-8/18)
% = [U2, R D R']   // insert 3c comm ( 8-2/24)

(R F R' F2 U2 D) B2   // X-Cross on R\UB (6+1/7)
(D L2 D2 L' D)        // 2nd pair on DFr (5-1/11)
(B' L2 B)             // 3rd pair on DBr (3/14)
(F' D F' D' F L2 F L) // ZBLS + LL-skip (8/22)

(F R L U)               // EO on UD-axis (4/4)
U2 R F L' D2 F'         // F2L-1p on D-FL (6/10)
(U' L' U L)             // EO on LR-axis instead (4-4/10)
(U2 F U F' U')          // all edges, leaving 5c (5/15)
(U F U' B' @ U F' U' B) // 3c comm (8-6/17)
@ = [F D' F', U']       // insert 3c comm (8-2/23)

B2 L              // EO on LR-axis (2/2)
F2 D' F2          // 2x2x2 on UFR (3/5)
D' B2 D B D' % L2 // 2x2x3 on UF (6/11)
B2 D B' D' B      // all edges, leaving 5c (5/16)
% = D' L F' L' D L D' F D $ L' // insert COLL for 3c (10-2/24)
$ = [D' F' D, B]  // insert 3c comm (8-6/26)

B2 D R2 U2 D      // Cross on B (5/5)
D F' D'           // 1st pair on DLb (3-1/7)
(U2 F' R F R')    // 2nd pair on DRb + 2p (5/12)
(R F U2 F' R' U2) // sq on Ubr, giving F2L-1p on B-UL (6-3/15)
(U L' U' L F2)    // sq on Fdr using Sledge (5-1/19)
(U L' U' L)       // direct finish using Sledge (4/23)

D2 L             // 1x1x3 bar on BL (2/2)
(R B2 U' @ B2 D) // 2x2x3-1e on BL-UB (5/7)
@ = F            // insert for edge on FL + edge on UF (1/8)
L' U R' U' L     // F2L-1p on L-DF using pseudo-slot (5-2/11)
R' D R' D'       // edge on UR + edge on BR (4/15)
F D' F' D        // all edges, leaving 5c, -3 on inverse (4-3/16)

skel: D2 U R' % U' L R' D R' D' F D' B2 $ F2 U B2 R'
$ = [B2, D F' D'] // insert 3c comm (8-7/17)
% = [R , D' L2 D] // insert 3c comm (8-3/22)

R2 F' U2 R D      // 2x2x2 on DBR + edge on UR (5/5)
F U' L2 F L' U    // pair on UBr + EO on UD-axis, giving 2x2x3 on BR (6/11)
L' F2 L F' @ L2 F // all but 2c2c using 2-gen (6/17)
[F', R' B2 R]     // 3c comm to convert 2c2c to 3c (8-2/23)
@ = [F L' F', R'] // insert 3c comm (8-7/24)

B (B) D2 R F'      // EO on FB-axis (1+1+3/5)
(L' B2 L2 U')      // 2x2x2 on UBL (4/9)
(U L2 D L2 U' R2)  // 2x2x3 on UB (6-4/11)
(R2 U' R' U R')    // EO on LR-axis (5-3/13)
(D F2 D F2 D F2 D) // all edges using 2-gen, leaving 5c (7/20)

skel: B D2 R F' D' F2 # D' F2 D' F2 D' R U' @ R U2 L2 D' B2 L B'
@ = [U, R' D2 R] // insert 3c comm (8-6/22)
# = [F2, D B D'] // insert 3c comm (8-5/25)

L F2 U'           // EO on UD-axis + 3p (3/3)
R @ D2 L F2       // 2x2x2 on UFR (4/7)
L B2 L            // 2x2x3 on UF (3/10)
L' D2 L           // EO on LR-axis + sq on D (3-2/11)
B' D2             // F2L on F, leaving A-Perm on B (2/13)
@ = [R', U' L' U] // insert 3c comm (8-3/18)

R L F U' B          // EO on FB-axis + 2sq (5/5)
R' D' R'            // 2x2x2 on DFR + edge on DB (3/8)
(B2 R B2 R')        // pair on BRd + sq on L, but breaks free sq on U (4/12)
(L2 U' L' U $ L U') // all edges using 2-gen, leaving 3c+1tc (6/18)
$ = [U' L U, R]     // insert 3c comm (8-8/18)

rewrite: R L F U' B R' D' R' U L' R U' L U L2 B2 % R' B2
% = B2 L2 U' L2 U B2 L2 D L2 D' // insert 3c domino alg (10-7/21)

R B' D'                   // line on FM (3/3)
R2 D' U $ F U' D          // X-Cross on F\UR (6/9)
D' B' L' @ D' B' L % D    // 2nd pair on ULf + corner on DFL (7-2/14)
@ = B2                    // insert for edge on DL (1/15)
D B' D' B2                // all corners, leaving 2fe (4-1/18)
$ = U' D R2 D' U F2       // insert 3e (6-8/16)
% = L B2 D2 F2 R U2 F2 D2 // insert 3e (8-3/21)
============================================================
found this first:
(L2 B' D' F' D2 B' R') // X-Cross on B\DL (7/7)
(R' L F L' R)          // 2nd pair on URb + corner on UBL (5-1/11)
(R2 # B U B' R2)       // edge on UL, giving F2L-1p on B-DR (5-1/15)
(R F' U F' U' F' R')   // all edges, leaving 3c (7-1/21)
# = [R, B' L B]        // insert 3c comm (8-3/26)

(F D2 B D')          // EO on UD-axis + 2p (4/4)
(B' U2 F' L' B' R2)  // 2x2x3 on UB (6/10)
(R F' R' F')         // F2L-1p on U-FL (4-1/13)
(F' D2 F2 L' @ F' L) // ZBLS + EP-skip, leaving 3c on D (6-1/18)
@ = [L B' L', F2]    // insert 3c comm (8-3/23)

(R' D L' B')     // EO on FB-axis + 1p (4/4)
(L2 F2)          // pseudo 2x2x2 on DFR (2/6)
(D L D2 U')      // XX-Cross on L\F + XX-Cross on F\L (4/10)
(U R U' D' R' D) // pair on DBl (6-2/14)
(R @ U R U' R2)  // ZBLS + EP-skip, leaving 3c on R (5/19)
@ = R' U B U' R U R' B' R U' // insert COLL for 3c (10-5/24)

R2 B           // sq on R (2/2)
D F2 L         // EO on LR-axis + 4e (3/5)
R2             // X-Cross on F\DR (4/6)
(D' U' B' U B) // EO on FB-axis (5/11)
(R2 D' R2 D2)  // F2L-1c on F-UL (4/15)
(L' @ B2 L)    // all corners, leaving 3e, -2 on normal (3-2/16)
@ = L D2 F2 U2 R U2 F2 D2 // insert 3e alg (8-4/20)

// Note: step 6 with (B2) gives 16-to-5c but insertions not as good

(L' F B2 L)         // sq on Bdl + 2p (4/4)
(U F @ U R2)        // X-Cross on U\BL + X-Cross on B\UL + 2c (4/8)
(B' F2 D' F D F2 B) // F2L-1e on U-FL using a conj (7/15)
(D' L D L')         // all edges, leaving 5c (4/19)
([L D' L' D, B'])   // 3c comm (10-10/19)
@ = [F', U R' U' R] // insert 3c comm (10-6/23)

(D2 F U' L B' L2) // 2x2x2 on UFL (6/6)
R F U' L' U F'    // Cross on U + 2p (6/12)
F @ D' F'         // 2x2x3 on FL (3-2/13)
@ = B'            // insert for EO on UD-axis (1/14) 
B' # R2 B2 R2     // all but 3c (4/18)
# = [F L' F', R'] // insert 3c comm (8-3/23)

(U2 R' U' L)        // sq on F (4/4)
(B2 U' B2 U' B)     // 2x2x3 on BR instead (5/9)
(B' U2 F' U F' U B) // F2L-1p on B-DL (7-3/13)
(F2 R') R'          // 1c - 1e + 1p, giving all blocks on inv (2+1/16)
(D2 B R2 F' R2 B')  // direct finish (6/22)
============================================================
interesting backup solution, with 13-to-3c3e:
U R2 F' R' (L)      // EO on LR-axis + 2p (4+1/5)
F2 L2 U F2          // sq on U (4/9)
B' U2 D'            // F2L-1p on B-UL (3/12)
(F2)                // 2c+2e on F, leaving 3c3e (1/13)
(F' D B2 @ D' F D B2 D') // 3c comm, -2 on normal (8-1-2/18)
@ = B2 F2 U' F' U F2 B2 D' F D // insert 3e comm (10-5/23)

(F' L U L U') U   // 2x2x2 on UFL (5+1/6)
(R' D2 B)         // 1x2x3 on Ub (3/9)
(B' L' D' L B)    // make pair for FRu slot (5-2/12)
(B' R2 B R2)      // 2x2x3 on UF (4-2/14)
(D2 B2 D B' $ D2) // all edges, leaving separable 3c+2tc (5/19)
$ = [B D' B', U'] // insert 3c, leaving 2tc (8-7/20)

rewrite: D2 B D' @ B' U B' D2 R2 B' R2 L' D L % D2 R U L' U' L' F
% = [L', D' R2 D] // insert 3c comm (8-7/21)
@ = [D B' D', F'] // insert 3c comm (8-5/24)

B L2 B'       // 1x1x3 bar at DL (3/3)
(U R U B' R)  // 1x2x3 on D (5/8)
(L D2)        // 2x2x3 on DL (2/10)
F' U' F U2    // sq on Ubl + EO on UD-axis, giving F2L-1p on L-UF (4/14)
R2 F R2 F' R' // ZBLS + EP-skip, leaving 3c on R (5/19)

skel: B L2 B' F' U' F U2 R2 F R2 F' R' D2 L' R' B U' R' @ U'
@ = [R U R', D'] // insert 3c comm (8-4/23)

(L R' D F' U F2 D R)    // pseudo-pseudo F2L-1 (8/8)
L (U') // premove + pre-premove to give F2L-1tc on F-UL (1+1/10)
(B L' B @ D' B2 D B' L) // all but 3c, -2 on normal (8-2/16)
@ = [B' L B L', U']     // insert 3c comm (10-5/21)
============================================================
found this first:
(F R D R2 U F')     // 2x2x2 on UFL + edge on BL (6/6)
(D B R B' D2 R' D2) // 1x2x3 on Dl, giving F2L-1p on L-UB (7/13)
(R' B' R2 B)        // sq on R (4/17)
(U' B U B' R)       // ZBLS using Sledge + LL-skip + AUF (5/22)
============================================================
very nifty 23 found after above 22 but before final 21:
(R2 B2 D') U      // EO on UD-axis - 1p + 3p (3+1/4)
B D2 L2 F R F' U2 // 2x2x3 on UF (7/11)
(B D2 B2 D2)      // F2L-1p on F-DL (4/15)
B2 L2 F (L2 F)    // make blocks with rNISS (3+2/20)
L' B' L           // direct finish (3/23)

(R F2 U R')  // EO on LR-axis (4/4)
(F2 R2 L2 U) // 2x2x2 on UBR (4/8)
D2 L2 D'     // F2L-2c on B-L (3/11)
F            // all edges, leaving separable 3c3c (1/12)
             // ran out of time looking for insertions

R' F @ U' F R        // 2x2x2 on UBR (5/5)
R L2 U' F' R B' U R2 // 2x2x3 on UR + EO on FB-axis (8-1/12)
L D L2 D             // all edges, leaving 5c (4/16)
[D' L2 D, R]         // 3c comm (8-5/19)
@ = [F' R2 F, L]     // insert 3c comm (8-3/24)

D B L D'       // Cross on L (4/4)
D F R F' D'    // 1st pair on UFl (5-2/7)
(R2 B' R B)    // 2nd pair on UBl (4/11)
(B' L' D' L B) // 3rd pair on DBl (5-2/14)
(R' D) D       // F2L on L (2+1-2/15) 
(R')           // CLL, leaving 3e on R (1/16)

skel: D B L F R F' R D' R B' L' D L @ R' B R2
@ = L' D2 L F' B D' R2 D B' F // insert 3e comm (10-3/23)

D' L2 # F2 L2 F2  // 2x2x2 on DFR (5/5)
(D2)              // premove to fix pseudo (1/6)
U' L' U L2 B' U   // 2x2x3 on FR (6/12)
B' @ L'           // all but 3c+1tc (2/14)
@ = [B, L F L']   // insert 3c comm (8-3/19)
# = [L2, D R2 D'] // insert 3c comm (8-4/23)

F2 R2 D (U)        // EO on UD-axis (3+1/4)
B2 R @ B' L2 B' U2 // 2x2x2 on UFR + edge on DR (6/10)
L2 B2              // F2L-1p on R-DF (2/12)
F L2 F'            // kick out free pair (3/15)
F' R' B D2 B' R F  // all corners using a conj, leaving 3e (7-1/21)
@ = R' B2 D2 F2 L' F2 D2 B2 // insert 3e alg (8-6/23)

R' D B2 D'        // 2x2x2 on DBR (4/4)
(U' F L2 U)       // 2x2x3 on BR (4/8)
(U L2 U')         // EO on UD-axis (3-1/10)
(F2 L F2 L2 F L') // all edges + 2x2x3 on FL, leaving 3c+1tc (6/16)

skel: R' D B2 D' L F' L2 F2 L' F2 @ U L2 U2 L2 F' U
@ = F2 L F2 L' U2 R U' R' F2 R' F2 # R U' // insert 2tc alg (13-9/20)
# = F2 R F2 R' D2 F2 L' F2 L D2 // insert domino A-Perm alg (10-7/23)

rewrite: R' D B2 D' L F' L U2 R U' R2 { D2 F2 L' F2 L D2 } R L2 U2 L2 F' U
{ = M2 // insert slice (2-2/23)
} = M2 // insert slice (2-3/22)

(U2 F' D R U') // 2x2x2 on UBR (5/5)
(D2 U L U')    // EO on LR-axis (4-2/7)
(U' D F2 U) L2 // 2x2x3 on UB (4-1+1/11)
(F @ D' F2)    // sq on Ful, giving F2L-1p on U-FR + EO on UD-axis (3/14)
(F D2 F' D2)   // all edges, leaving 2c2c (4-1/17)

skel: L2 D2 F D2 F D F' U' @ F2 D' U2 L' D2 R' D' F # U2
@ = [U,  F D  F'] // insert 3c comm (8-6/19)
# = [F', D B2 D'] // insert 3c comm (8-4/23)
============================================================
backup solution:
(L' D' F' U B2)  // 2x2x2 on DBR (5/5)
L2 F U2 L' F' L  // 2x2x3 on DB (6/11)
L' F R' F' R L % // EO on LR-axis (6-4/13)
F2 U F2 U'       // F2L on R instead, leaving 3c on L (4/17)
% = [R2, B L B'] // insert 3c comm (8-1/24)

U R' D @ F B U' F2 // sq on U (7/7)
(L' F U2)          // 2x2x3 on UL (3/10)
R' D2 R' D2        // F2L on L (4/14)
R2                 // CLL, leaving 3e+1fe (1/15)
@ = D' R' L B R L' // insert 5e (6-3/18)
R2 D U' B2 U D'    // 3c comm, -1 on inverse (6-3-1/20)
============================================================
backup solution:
(U' F' L' R') R   // EO on LR-axis + sq on B + 2p + Cross-1 on U (4+1/5)
(B')              // X-Cross on U\BL (1/6)
(B' D' F D' F' B) // 2nd pair on FRu (6-1/11)
(F' D' F)         // 3rd pair on FLu (3-1/13)
(D' B' D' B D')   // ZBLS + EP-skip, leaving 3c on D (5/18)

skel: R D B' D B D F' D F2 B' D @ F' D B2 R L F U
@ = [D', F U' F'] // insert 3c comm (8-4/22)
final: R D B' D B D F' D F' B' U' F' D F U F2 D B2 R L F U

U D B (B)         // EO on FB-axis (3+1/4)
U' # R L' D' @ R' // 2x2x2 on DBR (5/9)
L' U' F2          // 2x2x3 on DR (3/12)
L U2 L' U2        // all edges, leaving 2c2c (4/16)
@ = [D R2 D', L'] // insert 3c comm (8-5/19)
# = [U L U' , R2] // insert 3c comm (8-3/24)

U2 L F' R           // ext EO on LR-axis (4/4)
(D2 F D B R2 B2 D') // 2x2x3 on DR (7/11)
R' F' L2 F R        // F2L-1p on D-FL using a conj (5-3/13)
U' F U F' U'        // all edges, leaving 2c2c (5/18)

skel: U2 L F2 L2 F R U' F U # F' U' D B2 R2 B' @ D' F' D2
@ = [B R2 B', L'] // insert 3c comm (8-5/21)
# = [U', F D F' ] // insert 3c comm (8-4/25)

(R2 L U' B')      // EO on FB-axis + sq on U - 1p + 2p (4/4)
(U2 R B2 U' L2 U) // 2x2x3 on FL (6/10)
R2 B2 R2          // F2L-1p on F-UR (3/13)
U' L' B2 L U      // all edges using a conj, leaving 3c (5/18)

skel: R2 B2 R2 @ U' L' B2 L' U B2 R' U2 B U L' R2 // NISS cancel [L U]-[U' L2] (18-3/15)
@ = L U' B2 U L' U' L B2 L' U // insert COLL to fix 3c (10-3/22)

(F)         // 2p (1/1)
L F L' F U' // 2x2x2 on UFR (5/6)
L' B L2     // 2x2x3 on UF (3/9)
R' B R      // EO on LR-axis (3/12)
B D B2 (B') // F2L-1p on U-BR (3+1/16)
D' B' D2 B  // all edges, leaving 3c (4/20)

skel: L F L' F U' L' B L2 R' B R B D B2 D' B' @ D2 B2 F' // NISS cancel [B]-[B] (20-1/19)
@ = [B, D F D'] // insert 3c comm (8-5/22)

U2 B' L2 D2 @ F2    // pseudo 2x2x2 on DFR (5/5)
U R B' (B')         // 2x2x3 on UR (3+1/9)
(L' D2 L D2)        // F2L-1p on R-DB (4/13)
L2                  // edge on BL + corner on DFL (1/14)
D2 (D2)             // shift to gather 4 unsolved corners (1+1-2/14)
F U' F U F2         // all corners, leaving 3e (5/19)
@ = D2 L R' B2 R L' // insert 3e comm (6-3/22)
============================================================
backup solution:
L B L D'            // EO on UD-axis + sq on R - 1p + 1p (4/4)
(L' B' R)           // X-Cross on R\UB (3/7)
(F2 L F B' L' F2 B) // F2L-1p on R-DB (7/14)
(B' L' B)           // all edges, leaving 3c+1tc (3-2/15)

skel: L B L D' B' @ L F2 L B F' L' # F2 R' B L
@ = [B D B', U'] // insert 3c comm (8-4/19)
# = [L, B R2 B'] // insert 3c comm (8-3/24)

R' F2 D' R' B2 // 1x1x3 bar at DL + line at RE + line at UM (5/5)
(R)            // premove to fix line on RE (1/6)
L2 U2          // 2x2x3 using above blocks (2/8)
D2             // Cross on R (1/9)
L2 F L2 F'     // 3rd pair on DFr (4/13)
...            // rest redacted, sorry
============================================================
backup solution:
F2 D                // EO on UD-axis + sq on R (2/2)
(R2 F R' B L B)     // 2x2x2 on DBL (6/8)
(R2)                // XX-Cross on B\D (1/9)
(R' L F2 R F' L')   // 3rd pair on ULb (6-1/14)
(F @ R' F R F2)     // all but 3c (5/19)
@ = [F' L F L', D'] // insert 3c comm (10-6/23)

(L' B' @ R' # U2 L' D') // 2x2x2 on DBR (6/6)
(D F' U' D' L')         // sq on Ldb, giving XX-Cross on D\B (5-2/9)
(L D F2 D' L')          // 3rd pair on FLd using a conj (5-4/10)
(R U' R')               // all corners, leaving 2e2e+1fe (3/13)
@ = B F' L' F B' U      // insert 5e (6-2/17)
# = [L':L' R U R' L F'] // insert conj of 5e (8-3/22)

(L2 F R2 F2)    // sq on Ufl (4/4)
(U F' U' B')    // X-Cross on U\FL (4/8)
B R2 B $ R B2 R // F2L-1p on U-BR (6/14)
R D @ R' D'     // F2L on U + CLL-skip, leaving 2fe on D (4-1/17)
@ = D' R2 F2 L2 U' L2 F2 R2   // insert 3e alg  ( 8-5/20)
$ = B' R2 B R L' D' R2 D L R' // insert 3e comm (10-7/23)

R F2 L'         // EO on LR-axis - 1p + 1p (3/3)
D2 B' U F'      // 2x2x2 on UFR (4/7)
D2 B2           // Cross on R (2/9)
U' D2 F' D2 F U // F2L-1p on R-UB (6/15)
U' (U')         // shift (1-2+1/15)
F' L2 F         // corner on UBL (3-2/16)
F' (F')         // shift for +1p (1-2+1/16)
D F' D' @ F     // all corners, leaving 3e, -1 on inverse (4-1/19)
@ = R2 B2 D' B2 R2 F2 U' F2 // insert 3e, -4 on inverse (8-4/23)

D' R F' L D         // sq on F + sq on B (5/5)
L F B'              // 2x2x3 on DL (3/8)
(F' U2 F)           // F2L-1p on L-UF (3/11)
(R F R2 F' R)       // sq on Rdb + all corners, leaving 3e (5/16)
([R' D' L' U', F']) // 3e comm, -2 on normal (10-2-2/22)