In regards to using items held by companions at camp, I tend to just play it like I actually have them all with me, but due to gameplay mechanics and limits on technology, some people just have to be camped. I don’t really want to play a ton of characters at once in a turned-based game, but in real life I would totally have my whole group out and about with me if at all possible.
I had a blast playing solo. It’s not a game I would have ever, ever picked up if it hadn’t been free with PS+, because it didn’t appeal to me in the least. Got bored enough one day to give it a shot and I’ve got 100s of hours in it. Put it aside finally for BG3… for now.