summer performance and autocross tires

I run the Yokohama A052 on mine in an 18 inch size and I tell you they are terrible when they are cold. I mean less than 70 degrees out you can't get them hot enough to grip. If you are waiting between runs they would cool down too much or never get warm enough to be effective in cooler weather.

I have heard that about A052's. Are the RE-71R's still the "it" tire? I haven't been to an autocross in maybe 4 years. I plan to start again, next year. My car is almost done.

"you may just be less competitive"

I am really in it for the sport and to drive the car,, buy there is no draw back to doing well either.
And yes, I plan to run the Cam-T class.
Our Indy area SCCA has an Autocross event called a Drag - Cross, it is as it sounds a mix of drag racing and autocross. Two cars line up side by side for a Christmas tree start, then after some length each turns into their own duplicate Autocross course. Should be interesting.

SCCA has done that a couple times. I thought it had a different name than Drag-Cross.