[tentcamper]

I would look and see if you have the aux trans cooler. My 2012, I have a huge 2x stacked factory aux trans cooler. I'm thinking its about 30,000 BTU. It like 18" long and 5-6" high, by 2" deep. Looks a lot like a B&M cooler

Toyota recommends changing my TX fluid every 50K if towing, but lifetime if not towing. Toyota has has 3 different transmission fluids over the past 15 years. My understanding the older transmissions can use any of the newer ones. The latest one is very superior. For the 2010, I would check to see if you can use it when changing your fluid?? It might already be that fluid.

Is the 2017 a CV transmission??

For the 2017, I would think about getting the factory hitch. Compared to after market: It has more frame bolts, comes with new bumper trim and you end up with about 3" more hitch to ground clearance.