Compliments should be easy. Too much forethought will reduce volume and I would keep it simple to encourage volume. Yes, Quantity over quality.
"You did well on this grunge work" is a death sentence only if it's contrasted by silence. Maybe I have a blind spot here, but even if the compliment had to stand alone, does the receiver really have so little agency to not reframe or rebut any unintended consequences of the compliment?
Does frequency cheapen compliments? Maybe. Does every piece of praise need to be so weighty? I don't think so. "Please" and "thank you" might not mean much but I still like it when people are polite. So too effort can be recognized.