Changing the Idle Air Bleed(s) would be a nice idea. I don't have an Ultra XP carb. Drilling/tapping/plugging/re-drilling the plug is not likely in my carb's future.
Indeed, I have not checked my PCV in a while. While it could be stuck, I would expect it could be more of a low-vacuum-'leak' issue. I'll check that. (a btw): Putting a 1/8" 'restrictor' in-line would defeat the PCV being open when it's supposed to be, wouldn't it?