Tuning with jets, Power valves and an O2 guage

I reset the intial at 17. The advance stops at 31 degrees which occurs just shy of 2000 rpms. This was with the Distributor #1 in the form it has been since 2005. With the orange springs I put in distributor #2, the curve begins about 400 rpms off of idle and ends about 2400 rpms.
Just a question because I really do not know: Besides stiffer springs, is there any way to get this curve a little flatter? I mean even with 2 orange springs it just ramps up so dang steep.

Are you saying you loosened the two allen head screws under the breaker plate and adjusted the mechanical advance with the little red key spacers?