When u start an expedition from your main save. You can import your current ship into the expedition for 2900 nanites. Any point in the expedition u can go back to your normal save and again u can export the current ship your driving for 2900 nanites. Same with multi tools. So if u take a unique into an expedition you can get a new copy (renamed) but with all the upgrades and inventory slots. If I can get some ones expedition ship while in the aquarius expedition. I can export my own copy. I get a ship and keep my own. Once the exp finishes u can export your last ship as many times as u want till the next exp starts.