[eeegnu]

I've played speed chess for years, and I have never hit 300 moves in a game. The only way this will ever happen is if both sides are intentionally trying to avoid 3 move repetition.

And in terms of premoving, chess.com spends 0.1 seconds per premove whereas on lichess it's instantaneous, so I've found games tend to last longer on lichess move wise.