CStan
I mainly did it in order to be able to repeat the camber I wanted on the iron. I wasn't looking for any particular chipbreaker effect at the time to be perfectly honest. I needed the iron profile to be more or less the same as time went by. It made sense to me to profile the breaker that went with the iron rather than make some sort of template that needed to be dragged out constantly.

Otherwise, you question might be better put to David Charlesworth who apparently cambers his breakers as well. For once, it seems, I'm in good company and in a better neighborhood so to speak.

I never gave it another moment's thought until this thread came up.