This just seems crazy to me! Aren't you worried about bending the frame from hitting the bump stops?
I just recently went on a camping trip and had 2 big coolers, 1 in the bed and one in the back seat, probably combined weight of 300-350 I also had 3 15 gallon water tanks with a combined weight of 360, plus some other misc stuff maybe another 100lbs. My rear was squatting so bad I had only 1.5" between the axle and bumpstops. I had to pull the water off and load it in my brothers truck just to feel comfortable driving 100 miles.....
Im actually really sick of having to look at bump stop clearance everytime I haul anything in the bed and I've only had the truck a month. A bumpstop kit can't come soon enough!
Towing at or within the factory tow rating seems crazy? Nope, not worried at all. Guys will drive these things well BEYOND the factory intentions and not worry, there's no reason to worry towing them for what they're rated at, or even a little above. The frames aren't wet noodles that just bend. You do realize the bent frames came from guys hitting basically 8-12" tall mounds at near triple digit speeds. These aren't trophy trucks, but driving like one will bend a frame. Towing on flat road at highway speeds isn't going to bed a frame. Shit the frame is teh same as the f150 (or slightly upgraded for later raptors) and regular f150's can tow up to 11,300 lbs in certain configurations, on the same frame. ~1000 lbs tongue weight isn't going to bend the frame.
Also having the rear sagging a little and 1.5" bumpstop clearance isn't a big deal either. It's a bump stop, it's MEANT to be hit, that's why it's there. Now if you're desert racing, yeah you want more than 1.5" from hitting you bump stops hitting shit offroad at 100 mph. But if you're driving on the highway and hit a little dip in the road and hit the bump stop, it's not going to hurt absolutely anything. Most regular f150's have 1/2 the bump stop clearance that we do stock, and those guys will haul more crap than us, sometimes loaded up so bad it's riding on the bump stops, but you know what, driving on regular pavement, it's not a big deal. Not easy on the truck but not going to bed the frame.
Some folks are way too paranoid about the bent frame thing. You really don't need to check bumpstop clearance if you're just driving on the pavement and have the truck loaded up. It's still a TRUCK, you can use it like a truck, and you can overload it like most truck owners do here and there at some point. Offroading, little different story if you plan on driving it like a trophy truck. Onroad, it's worrying over nothing, you aren't going to bed the frame towing, or driving with 1.5" of bumpstop clearance.