I like the Perennial rye because of the very dark green color and finer texture than intermediate.
In regards to rust, Its shows up on the areas that are lean on N.
Same idea as managing dollar spot. Last year i got a little lean and i would notice my shoes would be orange after walking around. Avoid moisture stress and N deficiency. In our climate, it should basically be always growing and dark green.
I don't apply N to push growth for the horses although they munch it down to fairway height if you don't rotate where they graze. These horses are show horses and are not roaming a pasture. They are fed like kings in their stables.Since I can't apply any herbicides or fungicides, due to not wanting to take any sort of risk or being blamed for any sort of illness in a horse that cost 7 figures, I seed at a pretty heavy rate to reduce weed competition, do my best to get good seed to soil contact, and water the piss out of it the first 4 days to be sure I get good germination. Then back off pretty quick. I feed it after it gets a couple leaves and mow it once it gets to be about 4-5 inches and slowly lower the height so that you don't rip the seedlings.