Raptor towing 4,300 to 4,500 lbs

[Breathright]

We do/did a lot of towing this past summer with our Braptor and I've been extremely pleased with how well it does towing. The boat is a 25' Lowe SS210 that's 21' long with the trailer and motor making it about 26-27' long. Dry weight adds up to be ~ 4,300lbs and probably another 800lbs with gear and fuel. I have about 1" of droop and zero to no sway on the highway where i tend to try and keep speeds <70mph because the gas mileage is deplorable at 8-9mpg. Fortunately the trailer has brakes on both axels, so there's little to no additional stress to the braptor's brakes. Also, with the hitch i have, the spare tire does not stop me from having the hitch ball below the spare and therefore minimizing tongue weight (equal weight on both axes). I do however have to sometime connect the trailer to the hitch with the rear door open because the thingy that locks it on the ball is touching the spare, but then its fine once connected and the locking lever is lowered.
My question is other than more frequent oil changes are there other maintenance items that should be done more frequently? I've been rotating all 5 tires at 5K as well as oil changes at 5k but now wondering if i should have the transmission oil changed more often. TIA