So the combination of expedition and the core city factions update added a Lot of unique weapons and items but there are some things that i feel are missing
1st is that there are some catagories with no unique items (tabi boots come to mind, also not a single unique i.e. one of a kind belt exist s as far as I know) I would sugest something dancer themed for tabis and a bat themed belt that offers an additional slot over what would then be its inferior (and obviously less cool counterpart)
2nd is that the factions update added more uniques or more specifically uniques that offer truly unique bonuses to certain weapons/feats (that jkk one) it would be great to see some uniques that are make or break for builds
Lastly is the issue of unique items being generally under powered so much so that you would have to be derailed to use them when crafting exists.
Maybe add some sort of small questline that lets you either gain a feat that buffs the stats of any unique weapons you use by a percentage(that is based on your level so it scales).
or that opens up a way to permenantly improve unique items by using money, some new item (or hell maybe oddities), or just offers a limited number of upgrades fir the playthrough