@Itms How about making a 0ad community mod entry for 0ad in mod.io (0adcommunitymaps.mod.io)?
Instead of mods would be a zip with all the map data, the problem would be security concerns and review time (or none if is made as unofficial supported).
All maps would go to the same 0ad_communit_mods folder mod, of course would need some support from 0ad for compatibility reasons.