Hi,
I do not have any experience exporting, but if I am not mistaken, the problem is FBX. This is closed source and is being changed by the owner all the time….
There is a lot of work done by the Blender developers (mainly dr. Sybren Stuyvel, I think) to get better formats.
By the sound of it USD is very promising, but is not yet complete.
Could you use Alembic?
