Disclaimer: I don't own either bomb yet to test this myself.
If you run a duo where 1 guy uses Graviton Bomb and the other guy uses Freeze Bomb, can anything ever hit you or get away?
Both users charge up their bomb, Graviton places his and Freeze places right on top of that immediately afterward. Start charging again and move to the side a little bit.
Graviton explodes, drawing all enemies in, Freeze explodes holding them all there. New double set of bombs are being placed just to the side already, and explode before enemies can thaw.
Graviton hits all enemies, breaking their freeze and drawing them in. Freeze explodes once again sealing them in place.
Repeat forever.
Double Post for the lose!