It's sort of not.
SFM uses the files from TF2, HL etc etc based on their formats. HOWEVER, It will only use the INSTALLED cache files from Source games. So only official updates and content will be usable in SFM.
with that, because 3D software doesnt use sources (or rather, HL's engine), SFM wont recognise that object.
It's a bit hard to explain, what exactly where you planning to do?