I haven't looked at the mod in an editor in a long time, but probably it creates new bodyparts and alters the armor records to point to those new bodyparts instead of the originals.

The new meshes have a different folder structure and the plugin redirects the armor to use the new meshes. Completely pointless and could have been done in a different way.

Right but assuming the optimized mesh pointed to those same body parts (which it would if it was designed to replace the MGSO mesh), then you would not need to change the plugin. I haven't followed Pherim's work closely, but it's mentioned in the thread I linked that he is working in the armors, so I would assume that's what he's doing. Either that or he's going to provide a replacer equipment esp with his work.

Agreed. But it's not that hard to change the folder structure if you are replacing meshes. It complicates things but is not an insurmountable obstacle.

Perhaps putting all mod files e.g icons, meshes, textures etc into a BSA for that mod.

Thanks, but when I try to open MGE it just crashes. It requires external files like directx 9 and the download page for those files do not list windows 10 compatibility so obviously I didn't install them. I would rather never take another screenshot than risk any harm to my brand new computer. I suppose I will just have to put up with it.

If it crashes then you usually need to reinstall the required software for MGE and http://www.theassimilationlab.com/forums/topic/14138-how-to-installreinstalluninstall-mge/ is a quick guide for MGE. Just follow the instructions and if that doesn't help then let me know. Good luck Princess.