Figured there should be an update here since it's been a while. Been on a sort of semi self-imposed break anyway and also busy with other commitments (preparing for a con in 14 days), so I haven't been able to focus on the gamekit.
I still have a handful of bugs to squash after the now done big code cleanup stage, then I can get to implementing the last major features. For one, I've juggling how I'll handle an extra inventory, specifically the 'spoils bag' I mentioned.
Currently, it's proposed to function like a static inventory-set with a config much like the main-inventory and have the amount of slots be expandable by end-developers. I might even make adding extra slots config-side, just to make it easier, i.e, just edit the config to add a new slot/item type and boom, the game does it all on the fly without any further editing.
Another format I am pondering, while still using the config-option, is having only a single or few present icons and arrows and gamepad buttons to cycle/scroll through the entire bag contents, which is a bit of a different approach. Might even make it further like a slot-machine layout with columns/rows.