I think this is the fastest RG build out there. Cuts about 5 minutes off the combat time of other builds ive tried. Tower Boost doesn't drop at the end of the waves.
Make sure to place your inferno trap slightly closer than the other traps to the buff beam so that the summoner pets hit the inferno and not the other traps. Traps need to be on the edge of the ledge there in order to have LOS on the lower spawn.
Northern beam needs to be slightly closer to the center than the southern beam to catch the auras.
Upgrade buff beams before 1st wave starts, and run your summoner close to the auras at the start of the 1st wave. This will grow the aura's so that they hit the northern Buff Beam and hold that size. (Only has to be done once)
Notes:
Tb stands on the crystal, shooting East to the furthest spawn. Use your builder Warden and 2 range rate sumoners.