Mods for the SAGE engine are essentially always open source. Anyone can open your ini code, edit your texture files and import your w3d files. I would laugh my ass off endlessly if your mod was hosted by source forge. I suppose you could release what you've done so far, but it doesn't look like much if anything. :/
...Other mods don't give you access to things like texture sources (*.psd), 3D Model originals (*.gmax and *.3ds) and other things, only the raw output
Besides, people who make modifications to mods hardly ever see their work put back into the mod now, do they?