KCC right now gets stuck when moving up stairs when the character collider is very narrow.
This is because the player character can only walk up stairs when the player is "not falling." the player is considered falling when either they are off the ground or the angle between them and the ground is too sharp and they "slide down"
This can be fixed in one of a few ways:
Make sure the snap up feature will be able to fire off if it did the previous frame (this way they won't get stuck on a step)
Allow the snap up feature to fire off within x (configurable parameters) seconds of starting to fall
Allow the player to snap up steps even if they are "falling" as long as they are standing on the ground
Write a unit or playmode test to verify this behavior and that the player can move (mostly) smoothly up stairs no matter the size of the player collider.
Each of these solutions (1, 2, and 3) are not mutually exclusive but 2 has the best chance of working in the most scenarios. If 2 is implemented, it may be worth adding a short "coyote time" where the player is not considered "falling" until they have been off the ground for 0.1 or 0.05 seconds (maybe 1-5 frames). This allows for more easily understood platforming and moving around the map in a reasonable manner.
KCC right now gets stuck when moving up stairs when the character collider is very narrow.
Write a unit or playmode test to verify this behavior and that the player can move (mostly) smoothly up stairs no matter the size of the player collider.