Been towing with my 13 F150 Ecoboost since new. First with the old #5000 TT I used to tow with the 97 F150 with the 5.4. Different 5.4 than in your 09 however.. You could not give me a truck with the 5.4 3v in it... Garbage IMO..
Anyway, Moved up to a #7000 TT in 2019 and have not looked back.. I did have to switch to 92 octane fuel for the Eco however to take advantage of all of it's potential.. Which, BTW, has proven to me anyway, that it does make a difference... :)
You do gotta watch how much 'boost' you give it on the grades.. Those turbos will heat up the motor pretty quick. Also, don't lug the engine either thinking you are saving gas by lowering your rpms while towing... Don't work that way.. Yes, your rpms are lower, but your boost is higher, so it just dumps more fuel in it, and also creates more heat at the same time.
Keep the rpms around the 2200 range while on the flats and it'll actually give you a bit better mpgs than running lower rpms..
I'll give it a 'thumbs up' with the disclaimer that you have to know your rig and just not put it in gear and stab the go pedal.. :)
Good luck! Mitch