Maps can be items too

Why not? What difference is there between a map and an item? They're both a bunch of meshes, materials, and textures. Sure, you can specify more things to load with your map (xl, xa, ptcl, srs, halo), but other than that, there's no real difference.

You can definitely copy your map objects into an item file and have the client load it up. It'll load it no problem, but instead of an environment that doesn't move, you can move it around like any other item! Not only that, but you can combine multiple maps together (for whatever reason).

Though I've never actually tried this idea, but I think it is something to consider.

You will load all of the map-related files normally in mo00_00_00_08.lst, except instead of loading the xx file with the map files, you load it as an item separately.