Many thanks for making this RevOverDrive!
That code is very helpful, I was using the level BP for the camera actor movement. With this code I was able to place that code directly in the camera actor BP.
I see what you did there, it kind of makes a small edge or lip on the bottom of the wall, to reach the bottom of the player’s capsule before the wall does, kind of like the tines on a bulldozer bucket touching a wall before the bucket does.
I tried this and it does work!
https://vimeo.com/manage/videos/647497346
The problem then becomes when player jumps on a higher or lower platform and the edge is not there and the old problem resurfaces 
I see a few more issues in the vid I just posted, with player essentially sticking to the wall.
I would think then based on this approach the solution would be to do the opposite, attach a small cube (or body sized cube) to the player that would either push the capsule or be a boundary itself. Both cases would require that this “cube” would be a parent over the capsule component, and I could not get that to happen. Some error about the capsule is inherited and has to be the root for the character. Then perhaps a cube could be attached at runtime in the BP, but then how could you make it parent over the CC?