I definitely agree with you on the flawed nature of University tests and dry leaf tests in general. And I know there are people out there like you that swear by neutral zinc, and I’m glad it works for you. We have had very poor performance with it in pistachios, a very zinc-hungry crop and one that poorly absorbs it through its very waxy leaf. This wasn’t based on standard dry leaf tests, but obvious plant signs of zinc deficiency. Particularly up at the very top of the apical-dominant branches. The only thing that corrected the visual deficiencies was zinc sulfate raw at high rates or organic acid chelated zinc sulfate. Those are my experiences for whatever they are worth.