"... other than DS?"

I suspect it may be 'contractual'.

My understanding is that DAZ sorta-deprecate inclusion of OBJs, never mind OBJ+MTL, in new products. IIRC, I've seen several legacy items re-issued as a v2 in 'modern' DS format without their original OBJs. Vendors seem NDA-grade reluctant to discuss...

My feeling is that DAZ are trying to 'gate' the DS environment via their 'software bridges' and auto-install system.

Perhaps relevant that DAZ' provision of freebies has shrunk to one (1) page of oddments, with the occasional 'theme' pack as bait. The vast range of DS freebies on eg Rendo must make them gnash their teeth...

Tangential, has any-one succeeded in getting 'Make Human' FBX format to 'play nice' with DS ? Currently, the main rig breaks to a zoo of sub-rigs during Poser import, requiring geometric gymnastics to resolve. My impression is that 'Make Human' along with Blender, 3DOC, Open3D, Noesis etc etc etc etc all use the same open-source, reverse engineered code for FBX I/O, so fail like-wise.

Beyond a very few honourable exceptions, looks like Maya FBX rigs are the only fully-Poser-compatible type. But, given Maya's price, I reckon they've licensed Autodesk's FBX SDK....

FWIW, I'd happily buy a $50+ Poser plug-in that could correctly grok majority of FBX figures' rigs, permit full posing...

And, yes, while I'm out watching for flying porcines, I sometimes hope Poser imports would extend to eg PMX & XPS. SFM seems a bit-map too far...