I think of floor tiller, and long string tiller as accomplishing the same purpose, namely to get the bow bending enough to put a real string on without being over stressed. When floor tillering one end of the bow is on the floor, and the handle is pushed to bend the bow a little while observing the way it bends by eye. With experience you get a feel for how much pressure should produce how much bend. The rub here is developing the experience.
Long string tillering with a few extra precautions, like having the string length equal to the bow length, and pulling with a scale, can get the bow to brace height in a more controlled manner. If you pull with the draw weight, and get less than 1 deflection, there is no question, more wood needs to come off. However, even at 1 deflection you can still get some idea if there are large errors in the evenness of the bend.
To me, long string tillers job is done once the bow can be strung at a low brace height.
..Floppy disk?........ It is hard to find a computer that will accept one these days.