When a companion leaves the party they toss all their stuff in the PC inventory.
* Keychain
* Alchemy Pouch
* Supply Pack
* Backpack
* Pouch

And they throw quest items too. Even old quest items. Plus their gold.

Can we make this a setting instead of default behavior?

This is a lot more inventory management now, and I was totally fine with them holding onto a few hunderd gold, gemstones, food, keys, etc.
I kind of liked that they had their own stuff. Made them more real.

If I really need something specific I'll take it out of their pack.