Spawn cycling is basically 5v5 at beginning and after every goal. In between, after the first person dies (either team) they stay dead. After another person dies the first respawns and so on. It forces you to play agressive defense and more careful offense
but you would defiently have to get rid of pbox instagib... still i think it would probably do more harm than good cuz d would very powerful as they wouldn't die very much and O would therefore you would probably get a lots of 2 v 2 and stuff like that... sounds like a fun mutator but not good for game play