In my opinion and experience, there is nothing wrong, no harm done by having a trans cooler.
Again, in my opinion and experience, the harm happens with an overheated trans in the late rounds.
This feedback comes for many years of bracket racing and winning the final where the last 3 or so rounds come quickly.
I continue to say "in my experience" deal is, I always expect to be in the final and have equipment that can do so.
Consider Jeff Verdi who won the Vegas Million with a door car, I figger that car has a trans cooler.
OK, OK, rant over, sorry, no offence meant and I hope none taken. If there is a solid, documented reason not to have a trans cooler I will eat crow.
Yet will continue to have a trans cooler