I would never have a Cheat Sheet. But I do use a checklist.
I use it quite openly.
Instead of being a hindrance, I think it is a benefit in that the coach sees I'm going down a list and
seems less likely to interrupt with, "Say, let me ask you about this call I had in a game the other day..."
(I do this in another sport. In football, I'm the umpire and don't have a written checklist.)