Enable itinerant missions – Unless the mission needs you to return with a physical something, allow the mission to be completed at ANY mission board (i.e. not needing to go back to the original system). Perhaps not returning to the original mission board would have a % payout hit, like interstellar factors.
I want to be an itinerant worker, taking on roles and tasks and keep heading forward wherever the jobs take me, see new things all the time, not be forced to return to where I've already been just to get paid. I took down your damned settlement, delivered your thingie, or assassinated your target, etc., pay me.
It's one of the only frustrations I have with the current gameplay, it forces you to waste time retreading the same path over and over, rather than more fluidly forging your own path to enable the next gameplay and location experience.
This kind of QOL option would really help to resolve the feeling of unnecessary tedium grind.