With the original Mamba Max ESC people would eliminate the internal BEC and use either a separate BEC or receiver pack. This would allow use of 4s instead of 3s. I assume this is what he was talking about, but I dont know of anyone who has tried is with any other ESCs. I know Novak stuff does not typically respond well to use outside of it rated parameters, I have fried a few Novak products with only slight overvolting.
To do this you simply remove the red wire from the harness that goes from the ESC to the receiver. Then install a BEC or receiver pack.