I'll weigh in:
My personal thoughts & the majority of posts on this topic seem to point to a few key takeaways:
1. Most players are on-board or even in favor with the majority of the re-balances proposed here (which seems positive).
2. XP Return/Keeping the nerfed item seems like an agreeable solution for most items/circumstances, with two one BIG exceptions (Bodak lined armors & Electrum gilded armors).
3. Most players & devs agree that the return of crafted ingredients would be ideal, although it's not clear whether or not it would be possible to automate that return system.
With those observations in mind, I would recommend that things proceed as laid out by the Dev Team in all of the circumstances not pertaining to Bodak-lined armors & Electrum gilded armors. For Bodak, I would recommend one of the following (assuming that a means of automating the return of crafted ingredients is not found):
Bodak lined armors
Option A - Are grandfathered (I really don't think this is a big deal since the new system will allow for the creation of armors that still have /10 Negative Energy enchanted). Newly made suits with Bodak would not get the /10.
Option B - Bodak lined armors lose vs. death bonus, but maintain the /10 Negative Energy.
Option C - Bodak lined armors are re-compensated by DM's on an individual basis (I know there are many Bodak-lined armors out there, but I think the player sentiment here is strong enough to make it worth the time investment if no other solution can be found).
Electrum-gilded armors
(As I was typing this, I actually changed my opinion. The Bodak lined armors are a real issue. The electrum ones... I mean it's frustrating but I don't think it's worth losing sleep over really. I would say just keep the nerfed Electrum armor and accept that none of the gilds are going to be all that strong now).
Option A - Are grandfathered (This is a little trickier than the Bodak in my opinion since there won't be a gilding option with / DR post update, but there will be a lining option for /Acid). I don't think this is more powerful than other items that have been grandfathered in the past, but I know that may be a contested opinion.
Option B - I don't think it's worth asking DM's to individually compensate players materials for these, so I would say just swallow the pill fellow players.