I would question the need for a giant hotbar in BG3 to begin with. BG3 is not a real time game where you need to be able to do everything with one click.
Maybe we dont essentialy "need to" ... but i certainly "want to". :-/
Its much smoother to simply click and cast ... than open spellcasting window, search for spell, search for desired spell-level, and then cast ... call me lazy, but i liked it that way, especialy since Spells in Baldur's Gate refuse to be sorted by any key i found, and they keep sorting randomly.
That is main reason why i keep saying that *current* popup window casting mechanic is ugly, boring and stupid ... but to add there another mid-step would be totally crazy. :-/
