This > coaches who tell them to "just throw it"
ETA actually I want to add to this. My sister moved up from level 1 to level 2 last year, and that doesn't sound like a big jump, but it can be for a kid. At the showcase, her team didn't do jumps (bc they had changed the sequence that week), she didn't throw her running tumbling (and was supposed to), and her stunt dropped (and tbh it was her fault). They weren't a hot mess or anything, but others probably thought they "weren't ready" to be performing that. Well, physically they were, but the showcase allowed them to get in the right place mentally. At every comp that season, their stunt never dropped and she /always/ threw her running tumbling. It was better to make those mistakes in front of family and friends where it didn't actually count, and get it out of their system, than at the first comp (which for them was where they won their Summit Bid). I think even if you aren't going totally full out, a practice run in front of real people is beneficial. Or at least, it was for them.