trailer jack on a tow dolly

And better yet, the quick and easy answer, rather than polling the internet and inciting discussions that aren't pertinent to the original question, would be to go hook up, put toad on the dolly and see how much effort it takes to un-hitch it.
I "think" dollies generally center the toad wheel slightly forward of the dolly axle. For obvious reasons, including the potential for "summer" teeth" if there's any uplift pressure on the tongue hitch.