The iTunes client doesn’t allow this for the obvious ease in which content could be “copied without permission.” It’s no different with Firefly or iTunes as a server.
For your purposes, it would be best to create an open public file share. Remember to check your local copyright laws before distributing content. 🙄
Note that this say the “iTunes client” doesn’t allow it.
Also what’s the firefly memory usage? Is that 100mb? Or is that iTunes? I’d be interested in hearing how much memory firefly eats with a db that big. I would guess it to be significantly less.