Haha, definitely no master. I am learning everything from Fang, Richard, Marta and from literature and the YouTube videos.
If you see the grafted portion of the tree is drying up indicated by a wrinkled up look, definitely keep the rootstock suckers.
I actually keeping all rootstock suckers at this point because upon further research, the trees grow a dense rounded canopy. Allowing a couple rootstock suckers will not pull as much energy from the grafts as a mango for example. We really do need some male trees and the rootstocks seem to be at least 1-2 years old.
Simon