Endless import asset with animation from maya issues

Hi,
I know theres plenty of videos and docs on this subject but Im yet to find anything that solves (what I thought was) a pretty standard import scenario.
I have a character in maya that is skinned but also has constrains to hard surface meshes *helmet for example.
All the animation on these constrained elements have their transforms set to zero, animation is baked and the constrains are then deleted.
This is now a skinned character with some floating baked animation synced with it that is exported as an fbx and imported into Unreal.
In Unreal the skinned elements work correctly, but the baked animations vanish (not somewhere else in space, they just dont import)
I have spent 2 days trying every export/import strategy I can think of:
Ive tried exporting meshes with joints, meshes grouped and meshes combined.
Ive tried the Unreal exporter and Game Exporter and the fbx exporter with multiple settings.
and In Unreal Ive toggled and untoggled everything that I believe is relevant. but every time I just get the skinned elements.
I thought this was perhaps then the geo but its all clean, no transforms. Plus In Maya, Blender and Unity all of my test exports import fine.

I understand Unreal has a unique skeletal import system which is great when it works, but it rarely does for me and has proven to be a complete nightmare for any animation I import from Maya.
Any suggestions would be greatly appreciated? Ive used Maya for 20 years but Im still a novice with Unreal.
Again, to summarise, I just want a skinned character with hard surface bake animation element to import from Maya to Unreal.

Thanks

*Ive also tried just skinning everything, giving the hard surface elements 100% value… but that causing R6025 error, one of Mayas perks :confused:

So my work around for this is simple but not ideal.
Basically I applying 100% weight to the mesh to a specific bone. Problem here it its more time consuming, makes larger/slower files, and Im unable to play back in Maya (due to C++ fatal error) unless I reimport an exported fbx and delete the original. This also doesnt work if you need to animate the hardsurface elements independently.
Surely someone has had success in getting this to work?