A lot of complaints I have seen about this game is the inventory management… Something I think that help could alleviate this is when you go to talk to vendors in Sacrament to buy/upgrade or whatever you can access all inventory you have stored in chests inside your house.
It would take away from the monotony of having to remember what you have, and what you need, and walking back and forth between vendors and your house to try to make sure you have exactly what you need.
This would only apply while in Sacrament not when you are out exploring the world. I am not a video game designer but this seems plausible and would be a very nice quality of life change imo.