While i appcriate your idea in this, id say that ship has kind of sailed. With the new avernus ending cinematic she recieved.
If given the choice between that or yours where *the engine will eventually fail but lets live best we can for now* ending. Id have picked yours in a heart beat.

But the fact is larian alrdy put alot if work into that cinematic and got it out asap to try and get ahead of the outcry.

So i personally dont want them to try and create different *for now* endings. Id rather they focus their attention to a truly epic happy/fixed engine ending. Complete with beefed up questline.

But thats me personally.

With patch 4 i may try replaying a new playthrough durge as ive not had a durge play and as ive not experienced the new avernus scene or the new kiss animation.