Just like in Formula 1. When car exits from the pits and joins track there is white line you mustn't cross. If you do marshalls will give you drive through penalty. There is shot of WE track with that line. In online races people often don't obey it.
In order to prepare myself to longer races I did 60 laps race with AI today (BL1 track). At the beginning of the race I did some slides and was kicked by AI driver off the track. So I've got my R2 tyres cooked to 115 degrees. After 2-3 laps without slides temperature dropped to green range. And most of the race I've been able to keep them below 90 degrees. I've been using my slightly modified short race set, but camber wasn't changed.
Look at my tyres' temps at lap #32 just before pitstop.
By the way, I've forced AI to use my set but they were wearing R1 tyres when I was on R2
Nobody would race shitty track online so it's safe to allow online addon tracks.
Same for cars. Server may allow only one or limited number of cars so no selfmade batmobiles.
I'd like to see old Blackwood. S3 or new patch, whatever, might have say Blackwood 2007 (pre Y) and 2008 (Y) configurations. I really miss bankings there, older track was more fun.