It's not power, it's higher Gs, particularly lateral. So going to grippier tires is generally the issue. I had the issue as soon as I went 200tw at stock power, no aero in long right hand sweepers. Had it happen with 2/3 tank so just top off every session.
I'm impressed you still owe as much as that mileage being original owner. Probably not the best place for financial advice and too many details missing.
How much do you need all seasons? If not, check out the Kumho Ecsta Sport S (ps72 model). Have them mounted on '24 wheels with 265 front and 285 rear lowered on H&R springs. Watch tire racks video, really impressed with them for the price thus far.
I'd be interested. Not sure how many ppl would be needed for a group rate but Fontana Village would be nice spot for lodging. I'll also say some sort of scripted route would be best if it has a lot of ppl as someone is bound to get lost at some point. Would also say not June, July or August for...
Been on the OTS map for 18 months now with flex tune since summer and no issues. 14 track days as well. Is it perfect no, especially between shifts like you mention, but never any limp mode or codes thrown.