Any larger than 4 would need complete rebalancing of /all/ combat encounters in early access. If that was a prank, it was an expensive one
The killer argument is well known, as are counter-arguments, and that has been the case for a long time, not just yesterday or today... But precisely because of this, they could have been working on it quietly and secretly for quite a while.
https://forums.larian.com/ubbthreads.php?ubb=showflat&Number=672266#Post672266That being said, as explained in the thread, you can stick with a party of 4. But others would have the opportunity to increase their party.
At severe cost of unbalancing my game, yes. That's not a real "it's optional" and you know it. Party cap is what the game balances for.
I don't care how big the party size is. Any annoyance of managing companion approval can be removed by allowing 4-6 custom characters... which can be left at camp, if desired.
However, considering that you can make do with a very calculated party of 3 at the moment, 6 would require doubling the difficulty, in my opinion. Bg3 is an action economy. Your strength in combat does not scale well. The more companions you have, the more turns you can take from the enemy by killing it quickly. Two actions more and stealing 2 enemy turns by killing them, means 4 actions in your favour.
This can be compensated for, by either increasing enemy difficulty or amount. I'm not a particular fan of the consequences of either option, however. Some of your guys getting one shot by powerful spells would justify investing in healing. Being swarmed will let you feel party weaknesses better. Aside from these benefits, it adds unpredictably for the sake of it.
The only difference to 4 members is that turns will take longer, fights will take longer and you'll need more items. Not in the least to deal with the increased damage and status effects dealt by enemies. I don't care for that. It doesn't add anything of interest to my game.
If you have six companions, you might as well allow 8 or 10 or no cap at all. It's so incredibly over the top in decreasing difficulty, might as well go all in and make it another optional story mode feature. That is the only true optional path, besides making the game scale to your party size automatically. Say, for every new member outside x, enemies have +30% hp, x to hit, x to AC, etc. If it's not either of these two implementations, it seems too late to invest in.