Yes, I noticed the same thing with my NZ lemon graft. It had fruits early after I grafted it (less than 9 months), grew to full size fruits(2), and the grafted scion was only 5" long, not much leaves. I should have removed all the flowers and fruits since that graft is still the same size after 2yrs and leaves started falling off, the branch will probably die off soon. I had a second grafted scion done at same time which did not have any flowers/fruits until the second year and now that branch has grown large with multiple branches and very healthy. Moral of the story is to not let any small grafts have flowers and fruits, wait until all the branches grow out before letting them set fruit. My Buddha's hand is the same, the ones that I let flowers/fruits on first year grafts are growing very slow, the grafts with no flowers are growing much stronger.