Because Topanga is my beloved home town I feel I should at least try to help you out here, although, when I was caring for fruit trees there several decades ago, I didn't even know what grafting was.

Grafts take best, by far, on vigorously growing trees with grafts placed on upward, vigorously growing shoots- except when trees are ruthlessly cut to stubs and cleft grafts are placed on those stubs.

Grafts can be slowed by hormones sent down from higher up on the branch. To stop this downward flow scoring can be done where a sharp saw is used to cut into the cambium on the trunk just above the branch that holds the graft.

Here grafts can be slowed by aphids and leaf hoppers to the point where they just dry up and die or runt out. Runted out grafts can become spur bound where all energy goes into making flowers and fruit. Even picking off flowers early doesn't necessarily return such grafts to vigorous growth but that's what you have to do. Presumably, if a graft survives on a healthy tree it can eventually be coaxed to vigorous growth.