'18 F150 with 5.5 box tow a 5th wheel ?

I have a 2010 F150 with max tow and a 5.5 ft box. My trailer is a Security W26SLQRK with a 10 inch King Pin extension. The hitch is a Curt A16 Slider. When loaded to go, my truck axle weights are just about at max. I have been towing this trailer for a couple of years now through the Canadian Rockies and the windy prairies. I've had a few pull behinds over the past 20 years and this setup is by far the best I've ever had. I have also never used the slider. I have E rated tires, 3.73 gears, 6 speed trany and 5.4 l engine.