As lemontree wrote his post earlier, this is the kind of solution I like and also prefer. Fix her using gondians, do visit to avernus, do some bossfight, have few difficult choices in coversations, maybe few high rolls, meet her old friends, new dialogs about her life in avernus, improve her story in overall. After completing the quest sucessfully and if you care/romance her, very good ending (without/ with Tav) should be possible.
But all these implementations will need tons of time, if the original Avernus had the size similar to Underdark. Also we cannot forget, that there are other companions and their fans which also want to fix them asap. And content, ideas and features Larian want to add, update or rework. So at the end this will be a massive portion of content to create and implement into the game. Also this probably causes another issues like level cap, because player will reach level cap too early. To raise the level cap devs need to create new spells, abilitied and so on, balance the whole game so the ending will not be too easy. And so on.....
IF this will be implemented sometimes in the future in a form of definitive edition, I'll be the happiest BG3 fan ever. To be honest, I'm not fan of quickly added solutions as we saw in patch 2. It did some improvements, but in overal the Avernus cutscene looks average at best and feels even worse completely without emotions as my Tav in romance with Karlach stayed next to her like we barely know each other (If Wyll is with us it is even worse as she said the same things and Wyll is silent and looks like he doesn't care at all).
