Hey Pesky, I am assuming this is at your new hunting ground.
I am assuming you had something besides Ferns since you cut to 4".
You did not need to spray the second time, that is to kill the seed bank which will not sprout anyway in the late summer.
I never fertilize any of my Rye till the late freeze or first thing in the spring for my Clay, but you are in Sand.
You should shoot for six feet tall by mid July, not the wispy fields.
You are a young guy at 50 and can use the exercise anyway, besides you have a kid to help.
This is what I would do;
Buy a used cheaper Rototiller down at your house, get it now so you have something to work on this winter.
Leave it right out at your property covered.
Spray once first thing in the spring after it turns green then start Rototilling.
Dig and cut any roots you may hit that are at the circumference of the field.
Do not level the ground, all you are doing is packing the ground and letting pushing air out of the ground.
Buy a couple bags of Oats and a bag of 12's or 16's, no Lime, that's the last thing you want.
Throw the Oats and some fertilizer at the end of the day no matter what time of spring or summer.
Come mid August spray standing Oats to get rid of any Weeds that are there from your Seedbank.
DO NOT cut anything.
Throw your Rye heavy on the surface, the rain will flow your seed to the lowest spots and also bring the sand topping the seed.
Since you are in sand throw some fertilizer on top now.
If you can get some cheap Straw, throw that on top, it really does make a difference.
This will prevent the Birds from eating your Rye seed since they have been eating the Oats and are tuned to your field.
Fertilize again in the late winter or early spring.
Let your Rye get to it's six foot and let it fall naturally.
Weedwhack down and Rototill after and reseed with Rye but do not level.
You will be surprised how easy it is to Rototill once the original is done and may want to get some more exercise improving your plots.
Broadcast your Legumes in early spring after fertilizing as soon as it thaws.
I am a firm believer of having Deer food different than what is around for miles.
The Deer become acclimated to your food and will show up for the variety.
In your case, Small Burnet.
Once planted and taken care of you can get years or a decade with very little work.