Road miles are nothing compared to track miles though. It's kind of like 20 minutes of flat out on track would be the equivalent of a year of street driving in terms of wear. The heat generated during track use is completely off the scale of what road use heat would be.
DCT fluids are more recent formulations as I understand it than old style gear oils. My car is a '16 and had gear oil in it. I had not used DCT before, I was using conventional trans gear oils from Ford, Redline and BG that are thicker with the idea that thicker must be better. For syncros, it isn't. The damage starts with syncros, then gear teeth get chipped from syncros not working, metal gets shed into the fluid (why is there no filter in a trans??), bearings get damaged and on it goes.
There was a lot of damage in my gearbox using those old school fluids, they clearly did not do what they were supposed to do especially with the syncros, 3rd was the worst but they were all badly worn. 3rd gear was trashed as well, chipped teeth.
This new combination of carbon syncros, DCT fluid and a cooler is the best this trans has ever shifted. But you pretty much should go with what your trans builder is recommending if you want him to stand behind his work.
Regardless of what fluid is used, for a serious road course car a trans cooler is a must. I don't know of any commercially available trans cooler kits, which makes it a difficult task for the average guy to source out all the parts needed. I got everything I needed from Summit, with the exception of one fitting.
A lot of people feel the real fix is a Tremec, and there's good reason to believe that, but their gear ratios suck and they too eventually break down and need rebuilds.
Proving once again there is no free lunch!