Reimport FBX with separate meshes after adding bones in external 3D software

Hi there,
i got an fbx model of a cartoon rooster that has the eyeballs and other parts of the body as separate meshes and accurigged it by selecting all the relevant meshes.
That worked fine and the character can be animated.
I now want to add some bones to do some spring effects to parts of the body.
So i followed the official coyote character youtube tutorial and exported an fbx from CC and imported that into Cinema 4D and added the bones.

There are two problems now.

After import the character is only one mesh. No separate meshes anymore.
How can i keep the separate meshes after import?
And will all the weight maps and facial profiles that i did before the export be restored?

Also the bones that are imported are the ones i created earlier with accurig.
But Accurig does not recognice them and does not ask if it should “extrapolate guides from skeleton”.
So i would have to do a full characterization of the model even though the bone structure is coming from Accurig in the first place.

This workflow would be horrible if one would have to do all the mapping and everything again just to get some extra bones into the model.
Is there really no way to add bones in CC nowadays?

Does anybody know how to do this?

Not enough details to fully understand. But CC normally does not consolidate meshes which were separate under the root node.
However, if you had an Accessory type mesh and then export and import character back, the accessory would still be a separate mesh but under the root.
To keep it as Accessory, you have to save it in Custom Content > Accessory and then delete from character BEFORE exporting. After importing character back, reapply saved Accessories from Custom Content.

Face profile needs to be saved from Edit Expressions before exporting and loaded back after importing.

HIK (bones mapping) profile normally saved on export (there is a check box on FBX export dialog). So after importing back, you simply go to Characterization, load saved HIK profile and Activate it.

Finally in Bones, you set the status for newly added bones to “Used” and workout Spring for them.