You can still move the camera around and select pregame units.
Sometimes one of us ends up being put into the game earlier then others and the game world is basically frozen, I just call it limbo bug lol. However whenever the match is loading and we stay on the loading screen for about 10 to 15 minutes. Sometimes we have to verify the integrity of our game files in order to see our matches in the join game section.
We were able to join our lobbies and set our characters etc etc. Me and my friends had spent the last 3 hours trying to get Unification working via online private matches together.