Put a system in place, a "market" if you will, and let the player base create, and "sell" (for ARX or real money) interiors you can buy and put into your ship. Expand that to planetary installations, station rooms, corridors, dare I say, even ships!
Now Frontier doesn't have to "do" anything except provide a style guide to content creators and moderate the items. Step back, let the free money roll in (from content creator "license subscriptsion", ARX purchases with real money) and let the players do all the hard work, AND THANK FRONTIER FOR IT.
It worked for the Sims, it worked for Star Trek Online, it works for Flight Sim 2020, it worked for any number of other games that officially allow mods or other 3rd party customizations.
Frontier will never do this however, they have an iron grip on their game to the point of a strangulating the player base at times (HUD color customizations), but it's nice to imagine.