My thoughts on scheduling, as a racer, DE enthusiast, and founder of Apex Driving Academy. First, I almost never see any DE, track event, or test day with sessions in excess of 30 minutes. Even Chin when it goes to COTA will have 30 minute sessions. For races, unless they are enduros, 20-40 minutes is typical. If you are qualifying you better get it done in 3 laps or so as most tires I have driven have their sweet spot in that range.
In a DE environment, I find that driver fatigue, heat in brakes and cooling systems of street cars, and time to debrief and digest a session makes 20-30 minutes about right. Even on member days at MotorSport Ranch the standard sessions are 30 minutes and that is usually plenty.
What will hopefully be possible is to release a new group as the previous group cools down. If everyone pays attention to flags, it should be fine to release a group as the last car in a prior group gets to T12, provided last car acknowledges flags and has clearly slowed to cool down pace.
CoTA is simply spectacular in terms of technicality, long straights to enjoy power, check gauges and permit overtaking, and decent runoff for a pro venue. The runoff is also paved, so there is grip and you won't fill the car with grass or dirt. That said, T4 and a couple of other places can bite if you are careless, and you will be able to achieve 140+ at least 2-3 places, and the downhill entry into the T3-5 esses is very fast, so utmost respect is critical for safety.