Currently the 3D Space block only supports COLLADA, gLTF, and OBJ/MTL. It would be very useful to have two additional formats supported: FBX and USDZ.
USDZ is Apple’s format of choice for 3D on iOS and wraps geometry and texture data into a single file which is really nice for attachment purposes. FBX can also embed texture data.
OBJ/MTL is a really old format, and the external nature of the texture files in gLTF makes it cumbersome to work with in attachment fields.
Since this feature seems to be mostly for interior designers, I imagine that many of the models that an interior designer will be using in the short term will be USDZ.