Be careful Steve I'm not the only one now.
Enlighten us on your failed planting scenarios? When were your failed planting dates?
My guess is you have never planted it early Steve.
No need to be careful, as we agree on this at a rate of over 90%.
Each and every time I've planted cereal rye in WI, MN & MI, it's worked to perfection. Something you may want to experiment with is to not allowing your Cereal Rye planted last year to reach maturity this year. Just keep mowing it before it seeds out. I've done that a couple times and had not bad results.
I've planted it a handful of times with clover as a cover crop in the spring. I've also planted it a bunch with early planted brassicas (June, July & August). I've mostly come to the same conclusions you have, which is why I keep saying (both on the QDMA thread and here) that I think this is a great thread/topic.
Where I haven't had good luck with July planted cereal rye is in WC IL and MO. Now, I'm not making a blanket statement and saying a person will be disappointed if they do. I'm saying that I was, but there are many variables that could account for that. I believe the biggest was that none of these locations had snow cover for more than 10 day stretches and prime overwinter food was plentiful. On those farms, I was able to get deer to eat the very short, most tender growth, but they didn't hammer the taller, more mature plantings. In two of those cases, I used the mowing trick to get them on it (though one can't guarantee they wouldn't have anyway, they never did hit the tall cereal rye much in the brassica plantings I didn't mow on those two properties, which does indicate it was the mowing/reboot that helped...Planting later in subsequent years (in mid-late Sept down there), I did have good usage).
I'm in no way saying your advice is bad. In fact, one can make a strong case for planting early just to further build soils alone. I've had great success with early plantings further north and agree doing so provides more invaluable, cheap overwinter food. I suspect the same can be said for further south, in many situations. In my situations further south it just didn't produce the results I wanted. However, even on those farms, I could see how something as simple as an acorn crop failure could possibly change everything.