Can you tow more? yes but wear and tear and safety of you and your vehicle will be up to you. Remember the limits is up to you if you want to tow more just don't exceed the lowest rated part.
There are multiple related questions that don't all have the same answer:
- "can you tow?"
- "can you tow safely?"
- "can you tow legally?"
- "Who goes to jail if you exceed the published specs?"
- "Who comes up with the money when insurance refuses to pay for exceeding specs?"
- "Who deals with the guilt for possible injury or loss of life for exceeding specs?"
Engineers (balanced by marketing/sales and lawyers) come up with a "safe" rating that likely has a notable chunk of room that is still technically safe. The lawyers/insurance that get involved after an accident are going to go by what the book says, though.
Consider hanging from a 500' high bridge from a rope with a 200 pound working load. You weigh 250 pounds. The rope is probably actually "safe" to 400 or 500 pounds. Are you going to trust the 200 pound rope to stop you from splattering on the ground/rocks below?
I personally de-rate the published specs even further. For towing, I max at about 75-80% of the listed rate. Stupidity happens. Things break. Perfect-storm of small things happen. I like having the extra security. If I want to tow/carry at the rated capacity of a vehicle, I use "the next size bigger" vehicle to give me the reserve capacity.
Personal anecdote: I had a 6,000lb travel trailer and a Ram 1500. Once I added people camping gear, 500lbs of dogs, about 400lbs of "portable" kennel, etc. I was pushing close to the limit on the 1500. I traded in for 2500 to regain the reserve capacity. While returning home, somebody cut in front of me and slammed on their brakes. I needed to make an emergency stop. Braking took more effort than expected, but I did stop. Later inspection revealed that the wire for the electric brakes had been pinches/broken. I stopped ~13,000lbs of truck + trailer + stuff with vehicle brakes only.
It's a personal decision for everybody, and I'm probably "overly cautious". At the same time, I get to see "impossible" things happen regularly, and I've also never been involved in a towing accident...