The free ALS (advanced locomotion system) plugin has a GitHub repo which does this. Can use it as example (uncrouch, probably on animation BP).
Can’t review the code of your system that you didn’t post, but difference formula is always “Abs (A - B)”. (Use FMath::Abs)
I don’t know, I thought it gets its 0 location regardless of what the actor’s components are offset to. Might be wrong though since I’ve seen similar screwy systems in other engines and it seems you have tested this?
Still, you can get the capsule relative location and calculate the extension if you require.
If extremely minimal (to the eye), it’s a float precision problem. If it’s a capsule trace problem, you could still try a line trace, since you’re only interested in the line distance.