Since what you are towing is not a "factory approved" implement, and they don't know what you are going to do with it, it's far easier and less liable for them to just say "not recommended". As I said, my dealer TRIED to sell me one, so assuming you are fully aware of the machine's limitations, I would have no issue doing it. Just remember that a Grasshopper is not all that heavy in the back, and would be susceptible to too much weight behind the axle on the trailer, the rear wheels on the GH are small and wouldn't have much extra load capacity, and going down any type of hill could get REAL interesting. If all you want to do is tow a small lawn trailer around a fairly flat yard, and you don't load it with rocks, I see no problem. Like in most things, you just have to be smarter than the machine, which I understand is quite a challenge for some people. Just by asking the question, you've already proven you're smarter than most.