Not sure but re-launching from a different world might work

did you park it in the shipyard and then relaunch it? I thought I tried that once and it may have worked.

Kinda related question. The buildings that increase trade value. Do those only work on trade route homeworld? Or is it a global modifier. I think I'd care less about micro managing the homeworld if it were global for trade posts/etc.

easiest way to change the home planet of a freighter in my experience is to simply add that planet to the sponsor list of the shipyard that builds the freighter. the designated home planet doesn't even have to be anywhere near that shipyard. when the ship is launched, you can pick the home planet from a list of all sponsors of taht shipyard.

i actually used that little trick to make freighters closer to the target planet so it wouldn't take such a long time to establish the route. with the way the trade capital works, it makes very little sense to launch your routes from any other planet, so it's usually a good idea to use a single planet as the home for all trade routes. and since the trade capital and trade depot give a decent wealth adjacency bonus, that planet should probably focus on wealth and not on ship building anyway.

well at least it used to work like this. haven't played the game much recently. feel free to correct me if that mechanic was changed.