Existing CLL algs dont generally present much issue for this method, but ELL for regular 3x3 are usually not center-preserving, and can also involve many M moves which are difficult on shape mods. I have simplistically attempted to compute center-safe ELL algs with cubeexplorer, but the resulting algs arent exactly execution viable.

in the order they appear on algdb with their dubious naming sic'd

F’ U’ F2 D R U R’ D’ U’ F2 U2 F U’

U2 M' U' M U' F2 U2 M' U M U F2 (12s*)2-adj flip

U2 R2 F' U D' L' F2 U2 F2 L U' D F R2 (14f*) 2-flip

R' L U R U R L' B' R' D2 F2 U2 F2 D2 B (15f)bl-flip ua

U D2 R' U' L' F' U F R L U2 D2 L' U L (15f) bl-flip ub

F R U R' F' U F U2 F' L' U' B' U B L (15f) br-flip ua

R' U2 R U' B L F R U2 R' F' U2 L' U' B' (15f)br-flip ub

R2 F R U R U' R2 F' R U R U R' U2 R (15f)fb-flip h

R U' R' F' U2 F U2 R U2 R' F' U' F (13f*)fb-flip z

U2 R U2 R' F' U' F R U' R' F' U2 F (13f) fr-flip h

R' U L F R' F' R2 L2 B L U' L' B' L (14f*) lb-flip z

U' R U R' U' R' L F R F' L' U (12f)lf-flip ua

F' R U2 D2 L' U2 L U2 D2 R' U2 F (12f) lf-flip ub

U L' U' L U R' L F' L' F R U' (12f)rf-flip ub

U R' F' L F R L' U' L' U L U' (12f) rl-flip ua

F’ U’ F2 D R U R’ D’ U’ F2 U2 F U’

U2 M' U' M U' F2 U2 M' U M U F2 (12s*)2-adj flip

U2 R2 F' U D' L' F2 U2 F2 L U' D F R2 (14f*) 2-flip

**U2 R U2 R' U F' U2 F R U' R' F' U L' U L F (17f) 4-flip**

U R U R' U2 L U R' U' F U R F' U' L' (15f) 4-flip h

F' R U2 R' L' U F2 L2 F L2 F L U F U2 (15f)

F L' U2 R L U' F2 R2 F' R2 F' R' U' F' U2 (15f)U R U R' U2 L U R' U' F U R F' U' L' (15f) 4-flip h

F' R U2 R' L' U F2 L2 F L2 F L U F U2 (15f)

F L' U2 R L U' F2 R2 F' R2 F' R' U' F' U2 (15f)

**R L U2 R L' F2 L F R' U2 R L' F2 R F' R (16f) 4 flip z**

U R U R' U2 F' L' B' R' U2 R U' B L F U' (16f) bf-flip ua

U2 F' L' F U2 B2 U2 B2 U B2 U F' B2 L F (15f)bf flip ubU R U R' U2 F' L' B' R' U2 R U' B L F U' (16f) bf-flip ua

U2 F' L' F U2 B2 U2 B2 U B2 U F' B2 L F (15f)

R' L U R U R L' B' R' D2 F2 U2 F2 D2 B (15f)bl-flip ua

U D2 R' U' L' F' U F R L U2 D2 L' U L (15f) bl-flip ub

F R U R' F' U F U2 F' L' U' B' U B L (15f) br-flip ua

R' U2 R U' B L F R U2 R' F' U2 L' U' B' (15f)br-flip ub

R2 F R U R U' R2 F' R U R U R' U2 R (15f)fb-flip h

R U' R' F' U2 F U2 R U2 R' F' U' F (13f*)fb-flip z

U2 R U2 R' F' U' F R U' R' F' U2 F (13f) fr-flip h

R' U L F R' F' R2 L2 B L U' L' B' L (14f*) lb-flip z

U' R U R' U' R' L F R F' L' U (12f)lf-flip ua

F' R U2 D2 L' U2 L U2 D2 R' U2 F (12f) lf-flip ub

**F R U R' U' F2 L' U' L U F lf-flip z**

F' U F R U2 R' U2 F' U2 F R U R' (13f*)lr-flip z

F' U2 R U2 D2 L' U2 L U2 D2 R' F (12f)rf-flip uaF' U F R U2 R' U2 F' U2 F R U R' (13f*)lr-flip z

F' U2 R U2 D2 L' U2 L U2 D2 R' F (12f)

U L' U' L U R' L F' L' F R U' (12f)rf-flip ub

U R' F' L F R L' U' L' U L U' (12f) rl-flip ua

**U2 F R U R' F' L' U2 L F U' F' (12f)rl-flip ub**A possible compromise i considered is to only orient 3 E-slice centers during f2l, use LL algs that may rotate the last center (presumably R), then finally 1 alg to fix U and R centers. I am however not sure at all how much difference a constraint of 1 center would make on LL (cubexplorer surely didnt find that much better ones), plus i have been unable to find even good algs to rotate said last center pair.