Simultaneous exhibition premoves

[ddugovic]

Premoves are client-side so they can be canceled. Perhaps for simultaneous exhibitions there's room for improvement (in terms of quickly switching between games and remembering premoves).

https://lichess.org/forum/lichess-feedback/suggestionbug#1
"In this stream video of Lance5500 you can see a Blitz Simul where the Simul host (@Lance5500) tried to premove a few times after making a move on a board to save time since it was a 5+0 Simul. But the premove didnt go through and he had to repeat the premoved move on the board when it was his turn again.

I dont know if it was possible to premove in a simul in VS1 but since lichess gives the best opportunity to enjoy speed simuls, i think it would be a nice idea to make it possible." www.twitch.tv/videos/424171594