At the factory, they may start them up.
I know they take them for a lake test when the boat is all put together. Probably just before the final badging step. The boat ramp is about 20 mins from my house and I have seen the factory boats running up/down the lake. Assume there is checklist of things to look at, it's been years since I was on a factory tour.
Per the 2018 manual and not over 2000 rpms for the first hour - doubt that ever happens.
2018 Supra SL400