I think this is an excellent question, and I hope more people post on it. Personally, right now, I'm not at all sure, going more by instinct and feel. I try to be sane about alternating heavy and lighter, volume workouts, and probably try popping a 1RM for a PR once a month on powercleans, deadlifts, and squats. I can't bench right now, but since it is less of a compound exercise, perhaps slightly more often is possible.
I realize there are strict training protocols that address this issue with periodization, utilizing a precise schedule for when you should attempt your next 1RM. That requires not only strict discipline but the assurance workouts will not be missed. Sometimes, if I miss a workout or two, (due to injury or work) the rest can make me feel either stronger or weaker, and if it's stronger, I go for it. Doc