Option 2 works for me. I can now export as Maya cache and import it using pointcache modifier inside 3dsmax. no I have another problem.
In 3dsmax teeth mesh is attached to the face. after export to A2F, I had to separate mesh (Mesh menu → mesh separate) to character setup work correctly. so there should be an option to attach them back together again. otherwise vertex count and order cause problem in 3dsmax and pointcache don’t work.
In 3dsMax, find a way to drive final meshes (combined face and teeth), using multiple meshes. In Maya this can be achieved using wrap and blendshapes or custom nodes. In 3dsMax there should be a modifier or some other way too.
Update the original mesh inside 3dsMax, so teeth and face are separate meshes.
I was able to do drive the final combined mesh (face only as teeth and tongue setup is too complex) using A2F using Prox deformer. Please note this is not a standard workflow in A2F and is a little complex to setup.
I strongly recommend driving the final combined mesh inside other software as they have more tools for this type of deformation. A2F_Mesh_Separate.zip (29.9 MB)
I figure it out why my teeth dosn’t work correctly. I had several mistakes.
Picked UpperTeeth instead of LowerTeeth for the Gum/Teeth.
I forget to click on this buttons:
LOWER DENURE > JAW MOTION PREP
LOWER DENURE > TONGUE MESH FITTING
LOWER DENURE > TONGUE MESH POST WRAP