Probably need to use add rotation, not set.
Kinda sleepy so brain is slow, but quick and dirty example just spinning default Manny around with the mouse in 3rd person map:
Curve has keys at 10, 45, and 100ish with values of .1, 10, and .5 and it does speed up and slow down while turning. Is kinda fiddly though if turning too fast, so maybe not good idea?
No idea why rinterp wouldn’t like delta time. I pulled it of tick, but it should be the same as getworlddelta?