Long story short I had one, never installed and sold mine. I've never had any overheating problems with the transmission. Also, there is a limp mode the car will go into if the transmission overheats for any reason. Allowing you to safely pull over or drive into a safe area.
I instead went with an HKS oilcooler for my motor. I was frequently seeing 270/290 on the mountains and now I haven't seen anything above 220 in over year.
Are you planning on tracking your car? If you are in need of a tranny cooler check out this thread where you can read some information on someone installing and running one.
https://www.ft86club.com/forums/showthread.php?t=69139
Also if it helps a buddy of mine running a turbo AT FRS regularly tracks his at Road Atlanta. He's had no need for one.
cheers!