can you explain a bit more about what you'd like to do? What format do you want to export these models? And, for what usage? You can convert Form/Sculpt bodies to BRep bodies, and then all neutral formats will be able to be used for export. Or, are you looking to export these into another Sub-division surface modeling product?
Or there's a third option that the OP is looking to do, and that's the "Form Tool" function in the Manufacture workspace. If it is this third option, no, it is not possible to export these in any manner.
Hi @Anonymous .
In the past, I created an add-in to import/export form bodies. (The extension is .tsm).
https://github.com/kantoku-code/Fusion360-TSplineBodyDoorway
The format of the tsm file is supposed to be here.