I've always disagreed with you about the ending being entirely bad (sometimes in a not very pleasant fashion, which I apologise for), but I acknowledge the issues with continuity they created. And I've always been irked by Synthesis "space magic" as well. You've advocated for a full reboot before. Do you still think that's the way the series should have gone, and if you do, how would that be any better than jumping to a new galaxy?
You're right about there being lore issues. Chris' wormhole idea in the Twitter thread would be an acceptable way to get around that, but it doesn't change the issue I have: forcing us to give up a rich and mostly unexplored setting which we've become attached to.
Reboot, exile, AU, honestly I don't think there is a good answer, I acknowledge that. I know I would prefer something akin to an AU. But a soft reboot would be acceptable if done right (and this is indeed a soft reboot)
The problem here is, yes, lore issues. And abandoning all the familiar touchstones from the trilogy. Unfortunately, Bioware burned the house down, and are unwilling to rebuild. So the only option left is to move.
So what I'm left with is "What would make this option at least acceptable?"