Unfortunately, no. Also, due to Quake2 lacking a VM of any kind, crossplatform requires that you compile separate gamecode files for windows, linux, mac, etc. And since very few (that I''m aware of anyway) Quake2 mods ever released the gamecode source separately...
I'm planning on making a Quake2 QC codebase for use with FTEQW once I finish getting my new QC Codebase / FBX Upgrade finished.
Some of the things I'm planning for this project include changing the game to correct the gameplay flaws, and be more consistent with Quake 4. (which was a decent game, despite the lack of exploration that Quake2 had)
On the roadmap for this:
1. New weapon models / mods for most weapons. Chaingun would be replaced with Nailgun for example.
2. New models (and in some instances new monsters) for certain monsters: Engineer, Icarus (should be Jetpack Tactical IMO), Berserker, Light Tank, Iron Maiden, Gladiator, etc.
3. Vehicles, for great Metal Slug-ish Justice. >=D (Hovertank, Slug Gunner-esque walker)
4. Maybe a few new maps for better bridging, vehicle fight insertion.
5. Upgraded FBX for DM play.