For last weeks I was experiencing strange issue because when I used functions crouch or uncrouch character (default crouch system), tiny offset during capsule update was visible and it was not looking good. Today, I did some investigating (analyzing original crouch system, changing values and conditions… I spent a lot of time because of this simple issue) and found out that my crouched capsule half height is lower than capsule radius (just 4 units) and that causes those strange issues.
Feature Request: Add some kind of warning when capsule radius is lower than its height, I think it should never happen… maybe auto clamping height in code is good idea too