I'm struggling to understand how you are dumping in 1/12th scale mod

I'm not a top contender at the UK National level, but compete in the series. Running anything from a 12x2 down to a 10x1 I don't dump. Sure you go soft towards the end if you jam in the beginning, but part of the craft of 1/12th scale is to time the drive to suit the demands of the race.

Perhaps you are running outdoors and require more "go".. ?
In the UK we race indoors on carpet and typically my MMPR is between 36 (10x1) to 40 (12x2). If you are trying to pull 45+ then duration may be aproblem, but them you aren't getting best efficiancy from your motors. They sould also realistically be set between 12-18 degrees advance, more than that then they are being overrevved.
My 1p's worth, HTH