Agreed, managing the inventory is always tedious and some extra QoL features would help even more.

Having the same sort/filter in both barter and trade windows would help; I don't see why it's only available in the trade mode.
Also, a key/click shortcut for the 'Wares' tag and a dedicated filter in the inventory would help a lot. Especially since there's a bug that makes 'Add to Wares' clumsy at best.