Don’t tighten your KH holders down tight
UDC UK Roger pointed this out a while ago. Flip your KH upside down and spin the wheel. It should spin freely about 15 revs. Now tighten the caps down and spin it the same. My KH 20 dropped to only 4 revs. So I loosened the caps until it spun free again. Despite being machined quite close, KH holders aren’t meant to be tightened down tighter then other unis.
I haven’t had trouble with caps working loose. I would think either the nylock nuts, or blue loctite would fix that.