are you using Sketchfab app to view sketchfab models and wondering about bluetooth integration? so it seems like that would mean we'd need to request sketchfab add this functionality to their app. But they mostly have a different uh setup, not any thing to do with what you're discussing - i bet 99% people either have no BT controller or have a bluetooth controller but not an interest in viewing VR models with it. question - what do YOU use it for? Looks like architecture. did you know about AFrame. Custom made apps are pretty easy with that.
the weird thing is utopia which you mention has what you're talking about in this freely available sample:
i am 80% sure the code for this is free
find a coder and ask them to give you a way to upload stuff into this for you
don't expect 1 zillion poly meshes, but yeah #itschill