New Tire dilemma

[72Vega]

Here is my situation - I have an 05 Z51 with about 18K on the clock. The GY Supercars are down to 3 or 4/32 in the center treads and 5 or 6/32 on the inside and outside treads - on normal tires that would indicate overinflation, but these tires haven't ever been overinflated -I'm not sure what that uneven wear indicates. Is that "normal" wear for these tires or an indication or what?? I am a novice autocrosser - just completed my 4th event on these tires. I really enjoy this new sport and will continue to compete even though I'm not very good at it....yet. Also, I have a seperate set of GY A/S runflats that I change out after each autocross. This set gives a much better ride as a DD. I need to decide whether to replace the Supercars with a summer tire (PS2s?? the new Firestone runflats??) or what? Or should I consider an R compound tire for autocross events and HPDE? Most of the other SS vette drivers (at least the fastest ones anyway) run R compound Hoosiers. Sorry if this has been discussed before. I usually don't hang out in this section. Any thoughts would be appreciated. Thanks. Paul