What is "too far from the core 5e game system" according to you ?
Discussing specific changes at this stage is less relevant than the philosophy behind them.
I totally disagree. To quote you, "Larian may release this game in about one year, which is still enough time to make significant changes to its design".
As you said we have already discussed and suggested many things. Talking about "the philosophy behind them" doesn't add anything valuable to our requests to change/improve the game for it to become better at release.
That's why I was asking but if your goal is definitely to talk about the philosophy, I'm out

Of course, Larian's total lack of communication does not help us not to become mad.
They should definitely give us more informations on what is definitive and what is work in progress (reaction system, spell system, companions, ...)