Seeing how the devs are prioritizing gameplay features (which is good), I think community-made cosmetics would be a nice long term investment for the game. It's cost effective given how it's pretty much slave free labor.
Obviously there should be guidelines. If the community is worried about cosmetics being too out there or weird, the items could be voted in. But in general I'm sure there are good ideas waiting to be given life. Creators could (and should) be credited in the item's description in game.
Planetside 2 is a decent example of a game that let the community design cosmetics that more often than not were very in line with the theme of the game, be it those cosmetics were paid. I do think there are passionate creators out there that would love to contribute to this game even if it's without reward.
A good compromise could be a reference to their Patreon name in the item description as well.
This would let people decide if they want to support creators who they think are making great additions to the game and want to see more.
Optional tie-in to player progression:
Points could be awarded to players every X amount of rank ups, giving them more long term goals and things to unlock via prestige.
I also just pulled this out of my ass. The idea probably needs more polishing. Thoughts?