Worries me about switching them out?Oh... guess I misread. The realistic part of me says GameFreak is probably not going to change accuracy thanks to size for specifically OHKO moves.
They did address flinching, but it could be because Dynamax would lose competitive importance if there was the possibility of the Pokémon being flinched in the three turns it gets to wreak havoc.
And if switched? Will they be able to transform again? And if a G-max move will cause flinching will it mame other D-max and G-max flinch?