I wouldn't count street driving as a heatcycling on an Atom, unless you push it hard on a canyon road. On normal street cars tires do get in the optimal heat range with regular street driving but it's hard to see how that would happen on an Atom. They'll still degrade somewhat, especially due to UV exposure and road debris but not quite as much as tires regularly do on other street cars from heat cycling.

Threadwear is not a regulated industry standard. Beware, there are many 200 thread tires that are really more like 40 or 60, aka cheater tires. Some tires are dual compound, which may last a long time cruising on the road but last very little on track, e.g. Michelin Cup 2.

The new 888R is fairly different than the old 888. My understanding is that old compound, which I did drive on for a while, was much more effective at low temperatures than the new one. The new one has a higher heat resistance. Odds are the new one isn't that good for the Atom. An old batch is better.