The NV Gaming Commission specifically states in the integrity doc here: See page 14, Section 1.400 RNG Process:
Technical Standard
All VP machines must NOT SELECT CARDS UNTIL THE DRAW BUTTON IS PUSHED. This includes on both the initial 5 card draw, AND any held cards. So there are two RNG stops.
1) When you push deal/draw or Max Bet on the initial bet.
2) After you've held all cards and press the deal/draw button again.
Hope this saves any time for anyone wanting to know and having to deep dive into it. I came across so much conflicting information between when you press the hold card, to the initial draw, and then the final draw. So this solves it. IGT games must stop the RNG when Deal/Draw is pressed.
Not that it really matters lol.. But if you've ever held 4 to a royal, you know that all that matters is when you press the deal/draw for the last time... and hope you don't have a sticky one from a previously spilled drink.
Good luck out there!