fast-import: multiple processes possible?

Hi, I have a user question, I hope that's ok. Actually, the end goal is development of a fast-import frontend. The fast-import manpage says that it is safe to run "any other" git operation concurrently with fast-import. It doesn't say if it is possible and safe to run another copy of fast-import itself.

The reason I'd like to do this is speedup. With sequential approach my frontend can only load each core on my system about 50%. If I could run multiple imports concurrently I could make it close to 100%, especially when feeding it blobs (which take most of the time).

Thanks for the advice.