I did framegroups with Quake using Dark Places. Dark Places allows for external framegroups files very similar to how Quake 3 does it. I'm not sure how FTE does it. I had hoped (back when I was doing that stuff) that FTE was going to allow for external framegroups files. Not sure if that ever happened.
Here it is.http://quakeone.com/forum/quake-mod-rel ... ramegroups
I also experimented with different ways to write animation frames. I have the source somewhere. I will check later if you're interested.