Well, we are probably wasting our breath here, since Larian, with all its upsides, is almost NOTORIOUS for being stubborn and sticking to their poor design decision no matter how much feedback they get against it (the obscene randomized loot system of their past games or the massively criticized armor system in DOS 2 come to mind).
I think we all must focus to push hard on Larian to make that changes(like when community give group initiative feedback), because party size is the basis for all gameplay balance. If these changes are not be made as early as possible, they will never be done at all.