I have run 24 lbs since I bought it. There is no way I would even consider 40 lbs. I can't imagine going over the 24 lb. I ride 90% of the time 2 up fully loaded.
I run 36 Front and 26 rear.If I don't check them they are still ok.
I run the same, as what is recommended by Harley. So far, with over 7k miles, front wheel and rear wheels look new. I am sticking with the recommended pressures.
Learned this lesson the hard way. My TG always comes back from the dealer with something like 42lbs in all three tires. I suspect the teenager they hire to do that job at the wash bay simply doesn't know or care.
When I pick it up from the dealer, the first thing I now get out of my trunk is my TP gauge, and put 36psi front and 26psi rear.