I know this poster is asking about growing Teff for grain, so this doesn't apply to their question, but I thought others who were thinking of buying Teff to feed as hay, may find it interesting.
We buy all of our hay every year from the same farmer. A while back he grew a field of Teff and asked us if we wanted to try some, so I took 5 ton to try it out. I don't remember if he mentioned the variety. He has not grown it again, because of some issues he had with it. We had the hay delivered to the barn where we store the hay fed to the bulls. If looked beautiful, fine and green. I figured the bulls would really like it. The bulls always have access to pasture, but we also limit feed hay in winter. It is fed in a round bale feeder that is set up on cement, so there usually is very little waste. For some reason they would always leave some of that hay and since it rains here most days in winter, we would end up cleaning up some nasty damaged waste in the morning. Now that we have run out of Teff, we are back to feeding an orchard, rye grass mixture of hay. They seem to clean up every bit of that, so I would not buy the Teff again.