Love this idea, was actually thinking of something exactly like this earlier. My idea was to tie it to the main quest. and eventually base it completely on teleportation tech. Then like you said use the relay grenades to call in your armor, Adjust some thing based on faction for flavor and you have an immersive way to call in armor. as far as multiple armors make it so you can craft your relay grenades, and make an armor mod thats a "Relay ID" that is tied to a specific grenade and you can craft grenades for your armors. You could build on this idea by adding in different effects when your armor arrives such as: Brotherhood: Surface drop, armor is in a pod and warps in in the sky above grenade, pod has rockets that propel it to the ground and has an amplified aoe fire effect similar to the leg mod. pod the opens revealing armor. "think something along the lines of Halo ODST" Institute: suit warps in and has an aoe shockwave that pushes everything back and knocks them down. Railroad: pod similar to brotherhood only it warps in underground and has a bit drill on top and comes up then opens to reveal armor Minutemen: ??? cant think of anything for them but you guys get the idea.