The current rules for any% specifically state that only 1 player is allowed, and then go on to tell you that playing in multiplayer mode (which is impossible unless I'm missing something) is recommended.

You can play a multiplayer game with only one player. This is what most runs do. Usually done through multiplayer -> host new game and then simply playing in the same way as a singleplayer game.

In multiplayer, when you open the technology tree, the time in the game does not stop (in single player - time stops). (sorry for my bad english).