The problems that i see using one, is trying to push a TT's weight up an inclined driveway or on grass/gravel/dirt. It works best on concrete..level concrete. Make sure its beefy enough and has a brake. Last thing you want is to be run over by your own trailer. :E
It is hard for me to see using the dolly :
I have a tight spot that i have to back my utility trailer into. I have 1" clearance on each side between a fence and garage.
I thought it would be easier to back in using a portable motorized hand dolly , so i converted my snowblower by adding wheels and a ball.
Although the home made dolly works ok for a lightweight utility trailer, it does not allow me to have a clear view of the sides as im backing it up. I can actually see better using my truck and mirrors.
The only time i use the dolly is when the neighbors cars are parked in the street preventing me to pivot out of my driveway.
Snowblower conversion will not work on a TT due to heavy TW and mass weight. It lacks the traction you will need unless you can fabricate a heavy duty rack directly over the drive wheels.