Sometimes, I am 90% sure that the game let me sell things thst were not in the hub. but, putting things in chests doesn't seem to work when I tried it. is there some specific mechanism there I am missing?

edit: thinking on it, I bet it is the missions specifically that look at random chests.

would be nice if either it always looked at chests for sale too, or chests placed adjacent to a cargobay/hub. though once I get to the point of rapid expansion, I suppose hub space won't be too expensive anymore.

You are correct — items in chests are counted for mission turn-ins, but they are not used when selling items directly. And yes, by the mid-game, regular chests are not really needed anymore. However, for the 'hard' and 'Very hard' difficulty levels, your suggestion makes a lot of sense, since the hub works in the 'old way' there. I'll implement that. Thanks!

That said, make sure that the chests must be adjacent to the hub or bays - If I want to save something and never sell it, it being not adjacent makes that safe, impossible to sell.

Or something, I dunno.

Since 0.9.108 chests are counted for trade too, not just missions — so selling from chests already works anywhere on the platform, and 0.9.112 uses the same rule when rescuing contents of a mined building.

Restricting it to chests adjacent to the hub or bays is an interesting idea and I'll think about it, but I'm wary: "adjacent" is easy to break by accident (you move a bay, and your goods silently stop counting), and the whole-platform rule is the one that's easy to predict.

For a safe you don't need the adjacency rule though — anything stored in a vehicle's trunk is invisible to trade and missions (only chests and the hub hold are counted). A car parked on the deck works as a strongbox today :)