Just this winter I this exact scenario. An SUV was pulling a 4-place snowmobile trailer around 70mph. I was about 1/4 mile behind when a linx ran out into the road. The driver swerved and the trailer pushed the SUV off the road and jackknifed. Everyone was okay but I would say that was certainly a case where the vehicle was capable of pulling the load in a straight line but not safely in an emergency situation.
Trailering is 5% vehicle, 95% driver. Your situation above proves that perfectly, as the exact same very likely would have happened with a larger vehicle. If you swerve in an emergency scenario with a trailer, the trailer is going to whip around. Snowmobile trailers in particular are evil little things to pull, I hate pulling my 2 place enclosed, would MUCH rather tow a boat around! An experienced driver would have been going slower, and there would be a dead linx.
I've towed WAY beyond vehicle recommendations, I had 4000 lb's+ behind a sports car. I've had somewhere double the rated load behind a 1/2 ton. But I like to think I was able to do it safely, I also grew up on a farm and have towed every type of load possible, with everything from a law tractor to a semi. When I see someone going down the road, I'm just as worried about the large truck with a pontoon as I am with a crossover and a tinny behind it.
Anyway, OP. I personally wouldn't, and not for the safety reasons. Don't know about your specific year, but Explorers have never been known for having a strong transmission. Pontoons pull hard all the time, lots of drag, and that is extremely hard on a transmission. Its easier to pull a heavy aerodynamic load than a parachute. The good news is that Explorer transmissions are relatively cheap, as there is a decent supply for cores out there!
