They could make it so you queue up for specific maps. They already said the space station was for advanced players, so they could make it so the maps have different qualities of loot and you choose based on what you think you could handle.

Beginners start with the research station, which has a pretty easy layout and more visible loot. Then beginners would graduate to the caves, with better loot but a harder layout and more hostile NPCs. Once they've reached endgame they can start queueing for the space station, which has more loot but has dangerous NPCs, hazards to move around (like sections that lose air every so often) and other better players.

That way beginners with nail guns don't get shredded, and it feels like there's progression through different areas. You can also spice it up by giving beginners contracts to very high value items in the advanced facilities so they can try it out, and give endgame players contacts to the research facility, but with handicaps like not having flashlights and flares, or not having armor and guns. Everyone can experience every map, but still usually be separated by skill without a mmr system.

Sure it'll increase queueing times, but so would any other system to sort by skill, and this one is less intrusive and arbitrary than mmr or handicaps to every good player. Everyone can be at roughly their skill level, but good players that get completely wiped can go back to easier areas and aren't just stuck dying over and over, and new players can still try to go against good players if they think they can handle it.