Heya
Has anyone made a plugin or a package to export to VRM yet?
I’m aware of loading into babylon, but I can’t find anything to export;
Nope, this does not exist so far but we gladly accept any contributions 
if you are interested ?
You can export to GLB, so if a program that imports GLB & exports VRM would do it in 2 steps (maybe blender).
This is the only package I’m aware of that can export VRM: GLB Export - VRM documentation which is already mentioned in the Babylon.js doc links you referenced.