You only need to run a few tanks, two or three maybe, sometimes more to iron out the kinks and get it adjusted reasonably well.
You really need to heat cycle the engine as that helps it run in much faster than simply hooking it up to a gallon of fuel and letting it run non-stop.
You want the engine to heat up and cool off. Also at first you want to run the engine for short period of times at a rich full throttle and then back it off to a high idle letting it cool off, then repeat. As the engine gets run in more, the full throttle intervals get longer and longer.

Heat cycling is where you run the engine for a few minutes and stop it, let it cool off, then repeat.  Some engines, such as the vintage free flight ignition engines from many years ago, only run a small fuel tank for maybe a minute or less and then you let the cool off and repeat the engine run, and so on. You couldn't run these engines very long, especially at first when new.

Now with the ABC engines, they basically run them near their top speeds as you need them to heat up and expand the cylinder out straight so the piston doesn't get shrunk down with the swaging effect from the tight taper or pinch in the cylinder. But you still need to run them on the rich side some at first though.