I'm almost done with the extended plasma research. It works like this:
You will be allowed to research alien plasma weapons and learn how to use them but you cannot manufacture them, including their ammo. Once you have researched all laser tech, Elerium 115, Alien Alloys and all alien plasma weapons and their ammo clips, a new research topic will appear, Plasma Weapon Adaptation. When you finish researching it, you will also get a free research, Human Plasma Pistol, and be allowed to research the rest of the human version of alien weapons, and also Plasma Defense and Plasma Cannon for Craft and HWP. There's also a Tank/Plasma HWP, which is available as soon as you research the Plasma Cannon.
I will do something similar with the rest of the alien Tech.