it would be nice to see the option for custom servers to alternate between a turn based or a live action ruleset. If you remember Pillars of Eternity 2, they released, some time after launch, a very popular turn-based ruleset.
Same goes for Kingmaker. The turn-based mode was not very popular for either, at least not in the sense that it distinctly improved sales.
Anyway, slowing down RTwP to a crawl works, speeding up turn-based so that it isn't banal and boring as well as fun in multiplayer requires quite a bit of work. In other words, it isn't going to happen.
Not once in my years of playing tabletop DnD5e have I found its turn-based combat boring, despite controlling only a single character. I'm not too worried it's gonna be that much worse in BG3, especially with the improvements to combat speed and fluidity that they're making. But hey, maybe that's just my preference.
I believe games are best played in the mode they were intended for by design. Pillars of Eternity was clearly made with RTwP in mind and was really fun when played that way, but its turn-based mode came out very clunky as a result. Pathfinder: Kingmaker on the other hand adapted a turn-based system to a RTwP game, which made me enjoy its turn-based mode far more than the default RTwP - it just felt so much more natural and fitting for the Pathfinder ruleset (although the TB mode was very slow, and in inconsequential fights I was very glad RTwP was still an option). Same goes for Baldur's Gate 1&2 and their real-time-but-actually-not-really combat.
By the way dlux, regarding P:K turn-based mode and sales, do you have any sources on that? I'm genuinely curious. An unofficial TB mod has been available for quite some time, I'd hoped it may have improved the sales at least a little bit by attracting TB fans.