Corn and Rye bourbon method

[Midwest]

I have been running UJSSM now for 9 generations and feel comfortable in running the still and still learning on making good cuts. I would like to take the next step into all grain. I have been looking at Jimbo's easy ½ barrel and intend to try that initially. That being said, I have been doing extensive reading and want to put together a mash bill that incorporates 20% Rye. I'm laying out my procedure step by step and would like for anyone that could, look it over and help me tweak it, shoot holes in it and make corrections. Thanks in advance.

Ingredients
32lb corn, Dent corn milled to coarse meal with Corona mill
8lb malted Rye
18 gallons water
4 gallons backset (or combo of water/backset to reach proper Ph)
8ml SEBamyl GL
10.5ml SEBstar HTL

Fill my spare Keggle electric boiler with 18 gallons of water.
Bring the temperature of the water to 150 degrees and add it to the fermenter.
Stir in the 32Lbs of corn
Adjust the Ph to 6-6.5 if necessary
Add 10.5ml of SEBstar HTL (.36ml x 32lb corn)
Raise the temperature of the mash to 190 with steam injector. Hold temperature at 190 degrees for 90 minutes. Stirring frequently.
After 90 minutes add backset and/or water to adjust the Ph of the mash down to 5 increasing total volume to 22 gallons.
Cool mash to 145 degrees
Add malted Rye
Add 8ml SEBaml GL ( .36*20lb. The additional 20lb grain will get enzymes from Rye)
Cover and insulate for 80 minutes, or until Iodine test shows clear, stiring occasionally
Reduce temperature to 70-85 degrees depending on yeast.
Pitch hydrated yeast cover and begin ferment.

I'm looking to eventually make a bourbon with a flavor profile similar to a Four Roses single barrel. I know they use a little more Rye in that specific grain bill but this is going to be my first rye attempt and wanted to keep it simple. I also notice that some distillers grain bills, When I do the Diastatic math it doesn't add up. Is it a common practice in commercial distilling to supplement there malted grains with liquid enzymes? That is the only way I can make some posted grain bills work.

Another question. I know that Jimbo ½ barrel method will bring his water to 190 and then add into a fermenter and mix in the corn. Is that method of conversion going to yield close to a same conversion as the above mentioned method. It sure is simpler. Also if doing it the Jimbo ½ barrel method, would it be additionally beneficial to also use some HTL and Gluco enzymes to help things along?

Thanks.