Watching how abusive you have to be to the steering wheel and tires, the Auto-X is harder on the car than a straight up track day IMO. Certainly the brakes will last longer and you could probably do it on the OEM stuff as long as it's all properly broken in. Since you're not DD'ing on the R888r those will have massive grip on both the Auto-X and a track day.
You don't need to do oiling mods to run 100tw tires on a vette, do you? I know with s2000's once you go to 100tw or slicks you need to baffle the oil pan because the G forces will starve the motor from oil.
I think turns 7-8-9 is tough on oiling for LS motors in general at Gingerman if you are pushing the G's with sticky tires/slicks. I know that is also a spot where flat motor (BRZ/WRX) cars have some issues also with enough lateral grip, not an issue for how slow
sickmint79 is
. These are racecar problems for what I drive though (shitty lemons cars and fwd cars, sometimes both)
When I say brake mods you at least should do high temp brake fluid Motul 600 or 660 and good OEM pads, if you decide that you want pads to replace at the track that can handle the higher heat, don't get EBC pads, something like Powerstop Track Days , Raybestos ST-43, Carbotech XP 10/8 from cheapest to most expensive . Most newer drivers in higher horsepower/speed cars are harder on brakes than they should be as they brake too early and softly and from a high speed which just jacks up your brake temps.
Autocross is fun, but having to work sessions and sit around all day to just get 3 minutes of track time just wasn't going to work for me as I got older and had less weekends to race.