So let's say that you play with a friend and you are both performing actions that take some time (the progress bar shows up) and you would like to speed it up, but currently that's not possible.
So the suggestion is that the host should be able to skip time BUT when somebody moves the time would immidiately go back to normal speed (just like in singleplayer).
As an example let's say player 1 took wakeful trait and is currently reading a book and players 2 was tired so he went to sleep. Player 1 speeds up the time so that they would read faster and because of that player 2 would sleep faster. Player 1 then finished reading and time started to move at normal pace, after that they also went asleep with player 2.