Unlike the others who found this 19 I used DR-Xs for it. It might be interesting for some to look at the finding process. I think it's easier to find it this way because it doesn't require checking a 5 move EO.

First, slice EO is done for E/FB on inverse with already RZP 4c2e. This makes the DR-Xs free to find:

(F2 B2 U' L2 D) // DR-1s 2c3 (5/5)

Next you can switch and find a variety of reductions to DR. The one I first checked led to the 19:

F2 R2 D L R' // DR 4b2 4e (5/10)
U2 R2 F' L2 D2 F' // Slice + 4x (6/16)

This is already slice for DR-Xs. The centers can be solved by inserting an E2 in the first part of the DR-Xs finish.

This results in this solution:

(F2 B2 U' L2 D) // DR-1s 2c3 (5/5)
F2 R2 U2 D' L' R // DR 4b2 4e (6/11)
U2 L2 F' U2 R2 F' // Slice (6/17) +2/19

Most crucially I first only found +3 and was sure it was a 20. Luckily I checked it again and found the 19.