27-31’ trailers are not what I’d want to be pulling with a base model 6 banger truck.
There are many factors that will determine what is safe and why, and from a safety issue, there is no Inherent problem with what you’re proposing.
The super low rawr is sort of perplexing as I “think” all the 2015 and up F 150s have a super 8.8 rear end as the standard and the 9.75 as the heavy axle.
Does it have 10 or 12 bolts on the rear diff cover? If 12 bolts, it’s good for 4klbs plus all day.
If 10 bolt, I’d try to stay under 3500 for a constAnt long term load. That said, I’ve driven the snot out of many base model 8.8 F 150s with heavy loads many miles and no issues.
Bottom line, if you want a big trailer, and only plan on occasional towing, the chassis is up to it with good trailer brakes. 265 ft lbs though will s uck balls on every grade though.
You got the grocery getter model truck not the towing truck.