I’m also way behind in terms of fruit-set. Maybe we in the Northeast need a reflective ground-cover to maximize the sun. Or big computer controlled mirrors
Even getting the trees to grow seems hit or miss. Here are two trees which are next to each other (about 10’ apart) at a rental property. Both were planted in March 2017 from Trees of Antiquity.
Sugarcane, originally 9/16" and doing very well:
ShanXi Li, originally 3/4" and not growing much:
Of course, the 3rd tree in the line (a Li) was originally 1" caliper and has also done pretty well (maybe not quite as well as Sugarcane).
In the 2nd pic, you can see a failed bark graft on the ShanXi Li. I put one graft on each tree for pollination and backup purposes. The grafts on both of the more vigorous trees did fine.