but the new content seems like it only gets triggered after a full rest. Don't know if that's a bug or what, but I could have wandered around capital cities for hours trying to trigger Hirge's quest without knowing I needed to rest first.
I think this has something to do with how save game files work.
As you reload it, you reload already existing content (in save files), so you actually need to fully respawn area (any area) and to be sure, best way is sleeping for 12 hours.
It is something that was mentioned in many places, but not in this exact context.
About "loosing" equipment, it looks like mysterious letter (when you get to Adaon), I mean, after it you also need to get your gear afterwards. And, I guess anything and everything could be programmed, but real question is, how long it will take and is time to achieve this would be better spent in something else.