Baseplates and tow bars are naturally designed to be pulled but as you travel up and down and in and out through driveways, rough roads, etc. forces are exerted in all directions. These forces are much greater than the little pressure you would apply by backing slowly.
That being said as easy as my toads hook up and unhook why take the chance. I can easily unhook in less than 2 minutes and hook back up in less than 5 minutes.
Out of curiosity I pulled into the dirt field behind the house to see how far I could back and it is about four feet before the jeeps tires will crank all the way to one side or the other. In the dirt the front tires just slide but on pavement I think you would snap something at least prematurely wear out one section of rubber.