"I used to work at the Land Institute and kept in touch with them until a few years ago'
Google the land institute and you will find links to the publications by their scientists. Their methods are given in some of their publications. The last time I was up to date with them, they were growing many, 1000 or more, and harvesting each seperately. Thinopyron intermedium is self sterile and wind pollinated. So the seeds are pollinated by a mix of nearby plants After harvest, selection is for total seed weight, percent hulless seed. And maybe a couple other other traits I can't think of right now.
Last I knew, the name Kernza is copyrighted. You may grow and use it including replanting or selling, or giving, seed. But the name Kernza is copyrightefd so you can not call future generations Kernza. You may mention that it is desended from Kernza. You should check on this if selling as things may have changed since I have been in touch.