text: i think i need to try in JOSM, because what really needs to happen is most of these parking lots need to be separated into their own buildings, and only minor/easy features cross between them on layer 2. (maybe just roads as bridges, or even nothing. the buildings themselves don't really cross over except in the most literal sense, and i think that's the problem, because trying to make a multi-level building that doesn't generate errors is going to be a pain.)