I usually wait a week to accept an answer on any of my questions-- and by that I mean I always forget to go back and accept answers on all of my questions. I just went to like 10-20 of my questions and popped the green-check on nearly 20 at the same time.
Other than spamming @OrganicMarble, @RusselBorogove and @uhoh (I think I accepted 3-4 from each of them) is there any downside to bulk-accepting old answers to questions?