May I ask: what's the point of playing coop if you go seperate ways? You might as well just play seperate campaigns.
The point wouldn't be to separate all the time, but as an option, to accomplish different tasks simultaneously. Maybe Player 3 doesn't want to go save Mayrina. They could do something else during that part. That kind of thing.
But the main thing I'd like to see is the ability to leave custom party members at camp so that we can take premades with instead. That way, if I start a game with 3 other players and 1 quits, we can leave that 1 it camp and take someone else. Or, if we want to trigger Wyll's convo with the gobbo captain, we have the ability to take Wyll with instead of 1 of the PCs.