found the 10+2 too late

B R' B2 L'
U' D2 L2 D' F2 U' F' // 11 4b2
B2 D' R2 D'
L2 F2 R2 B2 // 19 slice +1

B' U2 D' F
R U2 R' L' U' R' U' // 11 0c0
R' U2 B2 D2 L
F2 R2 F B U2 B F' // solved 23

4a1 is the worst subset change my mind

(D2 R F' B')
(R U2 R' L U) // 9 2c4
D2 R B2 R D2 R' D2 F2 R
F2 D2 B2 R2 // 22 slice +1

D2 F D'
(F' L D2 B R' F') // 9 4b2
(R' D2 B2 D2 B2 L)
(U2 L2 U2 R2 B2 D2 B2) // 22 slice +2

why is every single dr on this scramble hot trash

(F L' U F)
(D') L2 B2 U' B2 U // 10 2c4
R (R F2 L B2 L')
(D2 R2 U2 F2 U2 D2) // slice 22 +1

even when the cool dr is good it's bad

(L U2 F')
(D R U' R' L D) // 9 4b2
D2 F2 U2 R D2 L
D2 B2 L2 U2 B2 U2 F2 // slice 22 +2

missed reasonable 23 from this dr and unreasonable-for-me 22
also spent time on the 10-move slice variant which has hard 23s

(L U2 F) B2 U' R' F2 L U2 L U // 11 2c3

U2 R' (R2 U2 L)
(B' [U' D B U' B]) // 11 4b2
U' F2 R2 D'
R2 F2 D2 F2 L2 // 20 slice +2

I wrote one 2+3 and it was this one.
of the two obvious 4q sols on inv, I tried one, the other gives 21, or you can do this trick to get a different slice that +0s:
[] = (R2 U D' F' U' F)

(B R2 L B)
R2 D (L' R U L' U) // 11 2c3 optically good, actually vile

(B') B' D' R' F
D2 L' B2 R2 L2 D R' // 12 4a2
U (F2 U)
(L2 D2 F2 B2 L2 F2) // solved 21

B U2 D F
(R2 D2 U R' U) // 9 4b2
(L' U2 R U2 R U2 R')
(U2 B2 U2 D2 R2) // 21 slice +1