That's a real good point Sprectralhunter, it's been hinted at the the magic inventory is a bug from adapting the Divinity engine to DnD.
A single inventory with the parties combined carrying capacity might just be the solution. The equipment page could then be used to distribute items for combat.(essentially if the player wants to use an item in combat it has to be equipped).
So if the player wants to use a potion in combat it has to be in the characters equipment (imagine if the character had a bag section that could fit 5 items, scrolls, potions, what have you.)
This could also be used to prevent eating food in combat, by having a rule to prevent the player from putting food in the combat pouch. (Just like how you can't have a sword for a helmet).
It'd totally be a workaround, one that would put the game in a healthier state.
This looks great, but definitely not enough "Larian".
Cow can climb ladders to avoid 3 clicks... They won't introduce consummables slots.