Thanks for the tip on 6B, I'll work on that the next time I get the chance.
66A+B does give a good wall-splat, and I hadn't thought about going straight into the PT instead of doing the usual wall stuff. I'm a little dubious about how practical 66A+B splat combos will be, if only because I see it as more of a mid-range spacing tool than a 50/50 option for wall mix-ups due to the slow startup. However situational though, it's good to know it can be converted for big damage under the right circumstances.
Edit:
Noticed a few things, and got some ideas from reading what others had posted.
What I thought I had noticed was that not all (high) walls are created equal. When I was practicing the 66K, W! combos I listed above, the B6B follow up worked 100% of the time against Groh on the Replica Kaer Morhen level walls, but was super angle dependent against Kilik on Snow-Capped Showdown's walls, which have a much more irregular shape. These were attempts from the default 'Wallside' positions in practice settings, mind you. I checked again on Groh on this level and noticed the same issue. I realized this had to do with how deep the 66K hits, as the reset spawn positions aren't the same distance from the wall. You can only hit the B6B follow up if the 66K hits late in it's active frames - early 66K won't recover in time for the B6 to connect.
The idea I got was to combine what someone mentioned about 2B+K~A+G after 6B CH near a ring edge with the existing combo formula.
66K, W!, B6B, W!, BB6, 22_88K, 2B+K~A+G_4A+G works, but you have to hit the 22_88K in such a way that you're still aligned enough to the wall for the 2B+K to hit.
Also, best damage I've gotten from a meterless wall combo came from this idea, and I hit the following -
66A+B, W!, 4KA, W!, BB6, 22K, 2B+K~A+G_4A+G = 125 dmg
This only works if the wall is closer to your left than right when you start because of the angle 4KA splats at. I tried it with a 22B finisher instead, but it was only 122 dmg with the scaling at that point.
Bonus SC Wall Combo
(SC Active) 66A+B, W!, 4KA, W!, 236A, 1B = 131 dmg.
(SC Active) 66A+B, W!, 4KA, W!, 236A, 2B+K~A+G = 143 dmg. I thought this was real but didn't have proper Ukemi settings on. If they don't Ukemi, this will hit them. Condition them to lay still.
I'm going to call it a night here, I've already edited this post like 5 times as I've been playing with these ideas. Hope some others can pick these up and run with them, maybe find further optimizations. I'll work on uploading clips of the above sometime tomorrow.
Edited Edit:
Ok I lied and kept trying things.
(Wall 45 degrees to left) 8A+B, W!, 4KA, W!, BB6, 22K, 2B+K~A+G = 140 dmg meterless. This is, however, insanely spacing dependent and finicky. This is a combo video only kind of thing - way too inconsistent to hit in a match that matters.
(Wall 45 degrees to right) 2A+B, W!, B6B, W!, BB6, 88K, 2B+K~A+G = 126 dmg. You have to use B6B from this side because 4KA splats in the wrong direction.
(Wall 45 degrees to right) 2A+B, W!, B6B, W!, BB6, 2A+G = 130 dmg. From this angle, BB6 gives you the backturned stun where you get the guaranteed crouching back throw. Doesn't work off of the 8A+B combo.
(SC Active, wall 45 degrees to left) 8A+B, W!, 4KA, W!, 236A, 1B = 146 dmg.
(SC Active, wall 45 degrees to left) 8A+B, W!, 4KA, W!, 236A, 2B+K~A+G = 159 dmg. They can Ukemi the last hit, 1B is guaranteed.
(SC Active, wall 45 degrees to right) 2A+B, W!, B6B, W!, 236A, 1B = 133 dmg.
(SC Active, wall 45 degrees to right) 2A+B, W!, B6B, W!, 236A, 2B+K~A+G = 146 dmg. They can Ukemi the last hit, 1B is guaranteed.
(Wall to left) 214A+G~8A, 6B, 22K, 2B+K~A+G = 89 dmg.
(Wall to right) 214A+B~2A, 6B, 88K, 2B+K~A+G = 89 dmg.
The spacing to hit 6B on this isn't very consistent, though. If they splat too early they'll slide down the wall before the 6B connects.
TL ; DR - Finish your wall combos with BB6, 22_88K, 2B+K~A+G. Best damage we've found so far.