Add a feature or mod where you can customize the gui scale for the hotbar, inventory, other containers, separately.
i.e
Hotbar: Large
Inventory Containers: Normal
Crosshair: small (you can already do this one with crosshair mod)
A bunch on other clients have had this for a long time now (Labymod, BLC, Feather), so I feel like this could be a a nice small addition to Lunar.