I don't mind the redundancy of this thread, it just allows me to try and distill my feelings through repetition heheh.
The main reason I would like to see a full party of 6, is so that this game will feel more like Baldur's Gate, which was one of my all time favorite games! Not Jade Empire or NWN or Kotor or Dragon Age or Mass Effect, and not Divinity Original Sin or Divinity Original Sin 2. But Baldur's Gate. I think if they increased the default party size from 4 to 6, the game would instantly feel more like a proper Baldur's Gate sequel and settle the waters on that point. The gameplay would then be differentiated from their previous Divinity titles, and I think it would just be a nice nod to the BG lineage.
In the Gold Box games it was a party of 6-8, plus 2 additional NPCs Baldur's Gate 1/2 was a party of 6 and up, since it also allowed for follower NPCs and various character summons at different points.
The games which came out later, and which went with a single AI Henchmen or a Party of 2, 3 or 4, just feel like they are coming from a different lineage to me. One that maybe still starts with old bioware dungeons and dragons style RPGS, but just not the one that I'm into, which is Baldur's Gate hehe. I mean that's why I'm here, that's what I signed up for.
It just seems like a very simple way, using systems already in place, to capture more of the spirit of Baldur's Gate. So that's my main reasoning, I have others, but that's the most important. Its to capture a "feel" more than anything else, one that BG3 is currently lacking for me. I hope they consider it, and build in proper support for 6, rather than just leaving all this to the modding community.
ps. I also fully agree with everything laid out directly above by GM4him. Not only would that be a better way to handle encounters, it would in my view heighten the replay considerably, since seeing how the game responds to different parties with different makeups or with different numbers, would then be another point of interest or potential surprise. It is perhaps not as interesting as an even more randomized system of encounters might be, but at least it wouldn't be static. Right now, if I've played the game before, I already know where the imps and flayers and gobos and such are going to be, what they carry, what they can do. Nothing changes from one play through to the next. Whereas if the encounters were scaling in some way, at least there would be a little mystery to it.