Hey Phil.
If you look at his picture of the rotors, you can see that the sides of the rotors have been ground. Grinding is the most true surface you can get. It looks like he did a good job on the machine work. We do not know how much material was removed.
The rotor housings are 80mm wide and the rotors have a slightly smaller width. If there is more torqe on the tension bolts, it can cause the tolerance between the rotors and the irons to be tighter. If there is too much material taken off the rotors during this clearancing process, there is going to be a problem with too much area of the side seals seeing combustion. Side seals, when they fail, usually anything it touches gets destroyed.
I know that Louis does a very good job on his grinding work. To be honest he is the best I have ever seen. I have gotten brand new irons from mazda that didn't look as nice as his lapped irons. I don't know much about his engine building skills, but if he does that kind of lapping work, I would trust him to build my engines. I am a do it all myself kind of guy too
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I have never clearanced rotors for any of my personal engines. I have made 435 RWHP on one and 440 RWHP on the other. The 435 car spun a bearing after 50K miles which is due to lack of oilmaintenance. The other is in my 1st gen which is still kickin it. I guess the true test will be done when the T72 goes on with the custom upper manifold....