Character Capsule Component Doesn't Interact With Physics Objects When Firing LaunchCharacter

I would advice against changing the movement component. You already have several ways to circumvent this which although “hacky” are not as bad as commenting lines in engine provided code:

  1. Use your initial approach with 2 colliders. If the size difference bothers you, make the original collider not interact with the boxes at all or disable it while launching.
  2. Make your own movement component and override the method in question. Quite involved and some methods are not virtual.
  3. Change the movement method - use Set Actor position each tick to avoid going through character movement component at all.
  4. Use root motion. (not sure if will work)