Normal operating temp for C6 in Race conditions

What is the normal operating range for a C6 launching off a brake with a higher stall converter? Also is it common to run faster times as the transmisison warms up? I ask these questions because during 2017 I only did TnT's but noticed that my Et's would get quicker as the engine and trans warmed up. The last night I was out before the track closed for the season, I ran the truck enough that the trans temp was up to 210F (going to add another cooler/fan this winter) but I got the best Ets I've had at this temp. Also had 2 back to back runs that were within a couple thousandths.
Don't know if it makes a difference, but I am running max life dex/merc synthetic fluid.

An ideal temp would be like 180F up to 220F . If it is working for you at 210F and that is the max then run it Keep an eye on the oil and change regular

There's plenty temp charts around like this

https://www.google.com.au/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwia-5bT1sLYAhVBGpQKHQUKD3YQjRwIBw&url=http%3A%2F%2Fgarage.grumpysperformance.com%2Findex.php%3Fthreads%2Ftransmission-cooler-info-and-derale-trans-cool-pans.662%2F&psig=AOvVaw1q3fA4say2qYNLtBzi5z2e&ust=1515305381668669

If you've ever done a burnout while watching the trans temp in the outgoing cooler line, it gets hot. Especially with a high stall convertor.

I like ATI's SuperF synthetic for hot usage.