Imma add my 2 cents to this conversation and say no, stick with 4. MAYBE 5, but thats absolutely it.
All this nonsense that players are saying about conversations should be with everyone involved, huge parties, and what have you. This is 2020, games are no longer easy, or handed to you. You have to actually -PLAY- them, and that means making, (everyone duck!), decisions!
Everyone can talk in one conversation? Offering their rolls to conversational choices? Why have choices at all then? You are loading the dice. How is this even fun when you "win" every conversation? Why. Roll. The. Dice. At. All.
6 member party? Why choose what classes you want to bring that would be best for whatever situation? You aren't making any decisions at this point, you are just freerolling and claiming a win for something you didn't Actually win in the first place because you started a combat with a loaded out squad.
To be completely fair to the OP, whom for the record is the exact same age as I am, down to the month, which is creepy and cool, their suggestion is essentially the creating of a different mode, which also includes a warning that this makes the game easier (I would use the word 'free', but I digress), I don't hate having more options, nor will I ever, but this distinction MUST be made.