It's interesting that you had positive results on cannabis with ethephon. I think it really depends on what plant it's applied to and the rate or frequency of applications.
It's mostly used to hasten ripening on field crops and fruit, but it's used on mums to delay flowering.
Ethylene is supposed to inhibit stem and shoot growth as well as stomatal closing.
Ethylene stimulates lateral branch growth.
I use to do tree work full time, mostly pruning and removals but for two weeks in the spring we would treat sweet gum trees with Florel to keep the fruit from setting. Timing was everything and it had to be done a few times in that two week period because the tree doesn't ripen evenly.
