I found a way for 15-20sec each match (excluding loading times)
Do this with 2people (including yourself)
=> Multiplayer => Custom Player Match
Select Game Mode = Deathmatch, Shapeshifters
=> Advanced Settings
Private Slots = 1 (I boosted it today and there where still players who played this and ruined the boosting)
Score Limit = 10
Auto Map Cycle = No
One Hit Kills = Yes
Join Game In Progress = No
Auto Aim = Yes
Maximum Players = 2
Weapons = SMG
Select Map = DM Death
Now invite the other player and if he's in the lobby start the game.
Do this in the warm up!!!
If you're the host you'll start on the street, directly go to the right
corner behind you (walk backwards and right) do this before the other player get's in the room.
If you did so the other player will spawn left to the hydrant, shoot him and make sure he doesn't push the respawn button! (take your time you have 5sec)
If you didn't move and he didn't push respawn, you will both spawn at the same location if the timer reaches zero and if the game realy starts.
All you have to do now is walk back to the corner and start killing him.
If you're the host and kill him quickly and he respawns quickly this will take 15sec.
If you're not the host you'll have to switch sides witch takes 5sec and bring the total time up to 20 sec a match.
I've found out this method myself by accident, I did it 100+ times and it only failed once cause I wasn't all the way in the corner.
Good luck, be patient and happy boosting.
gives us these tips in the comments:
Yeah, and sometimes you don't have guns in your hands. Just shapeshift into Darkling and back to Human. Now you have your guns and you can shoot.
One more thing. If I go to my boosting buddy during the countdown and shoot him he will spawn at the fire hydrant and the host will spawn where he started in the warmup.