Ya right now with mine i tested it with blender 2.79 for both mesh animated models and primarily bone weighted mesh animation is what i tested with the most. Exporting to Fbx. So like if you were building your own models in blender from scratch mine will work. (As a starting point as its no were near complete like i still need to rip stuff out and add tons of stuff that is on hold for now.)
For random models i tested dae and fbx work the best under open assest importer the rest no so much.
If you flip on the console and all the bools to true in the importer class at the top. You will get a shit ton of info for any model that will actually load in mine and can see how they all differ. Testing lots of different ones even in the same format you can see just how differently they are all structured its horrible.
Im actually considering writing my own format and model builder or editor directly in monogame.
The only really open and standard format i found was opengenx ogex but assimp wont even load that out of blender so.