Given similar Quake3 legacies, it would be maybe possible to integrate some stuff from OpenJK ( https://github.com/JACoders/OpenJK ) into the deamon engine?
Maybe it would be cool to have laser-sword fighting for human melee mechanics? The melee based combat in Savage2 for example worked really well in a FPS/RTS hybrid, and right now the mainly melee weapons of the aliens vs the mainly range based weapons of the humans make for a bit loopsided and maybe hard to balance gameplay?
Another interesting thing might be some single-player code (see also RTCW source release?) for some COOP mods or a tutorial campaign?