I think I’ve fertilized roughly annually with either a balanced or urea (N), but not too heavy.
Exciting update (at least exciting to me)- I found a number of small fruitlets on one of the 3rd year Shanxi Li. It’s a pretty decent sized tree 6’ wide, 8’ tall, so it’s good to see some production. The Li, Sherwood, and GA866 which are next to it (and also from ToA and planted at the same time) don’t have any set yet. But, I’ll be sure to check again in a few days 
Is it just that they loose the crispness? I remember saving a few one time for a couple months in the fridge and they started to shrivel a bit. Almost halfway between fresh and dried. Not as good as fresh, but I still preferred them to fully dried ones.