The problem with G1 is it’s not really a heavy class, just a skinny old farts class. With the puppies running at 385# and G1 at 395#, its really just a medium class. If it was a real heavy/old class, it would run at 410#. Tag Masters is 30# heavier than the puppies, not 10#. In my rose colored, totaly unrealistic world, the puppies would run on 375# and the heavy/old at 410#. Sam Walls proved that a skinny old guy could run with the kids.
Take a look at the first year of the CSC. Who won the Pro class championship?
Also, if you want to take a minute to look at history, look at the level of participation of the Briggs adult class away from IMI. That will tell you why its not in the CSC.
History folks, history. Don’t re-invent the wheel. Look at what was done in the past and why it worked and why it didn’t. Before there were any other tracks besides IMI, we only ran two 125 classes, novice and Pro. You were considered a Pro if you broke 54 seconds. If you showed up with an FC motor, like one racer did, you ran heavy, 420# if I remember right