And if so, why?
The spindle systems - tall spindle and super slender spindle - were originally developed for apples and have been adapted to cherries, so maybe UFO would work for apples.
Apples and pears can be trained to espailer forms on a trellis. I guess you could consider the ufo method to be just a form of espailer for apples and pears. Other stone fruits i'm not sure about.