Bumping this old thread because I have questions that echo the OPs, and I'm wondering if other member have had the opportunity to inspect their supercharger rotors recently. If so, what do they look like?

Please fast forward to the 1:45 mark on the OP's video in Post #1.

My quarantine project started with a Wilwood BBK, then ball-joints, then swaybar, etc. A week later and I decided to put the car in service mode, change the waterpump, and check/change the supercharger oil. What I found was that I had plenty of oil in both sides, and it as in good shape too. Note that the unit made no noises when operating and made full boost. It has 105k on it, but has only been over-driven for 10k miles. What threw me off was what I saw when I looked inside the inlet. The outer edges of the rotors showed wear identically to the OP's video at the 1:45 mark.
I'll note that like the OP, I have a blower with coated rotors on my JCW.

Now, because I'm an OCD Engineer, I dug into this a bit. Here's what I learned:

1) First, the black coating in the late-model R53 blowers is not Teflon. It's an abradable coating. This technology was invented and patented by Eaton in 2003, and rolled-out to the "5th Gen" blowers. The two inventors still work in industry, with one a chief engineer at Magnuson, the other running his own abradable coating business (Line2Line Coatings).
2) The purpose of this coating is to improve efficiency by reducing internal clearances of the rotating assembly. As the unit is ran, the abradable coating then begins to wear in certain areas (typically the edges of the rotor lobes) "self-tolerancing" if you will, creating optimized clearances and more power. This coating alone is what is responsible for the 5hp difference between '04 and '05 makes, as it produces ~1psi more boost than the uncoated blower.

Anyhow, back to my question: Who has recently seen their rotors, and did they look like the ones in this video? Only those with coated rotors need apply.
Dustin from AutoXCooper looked at the photos, and thought everything was fine. I'm also talking to Stiegemeier Porting later today for their opinion.

 

For anyone wondering, Stiegemeier Porting got back to me and confirmed that for this model my rotor wear is very normal and minimal, and not to worry if the unit is operating correctly and other areas (oil, gears) look good. Mine happened to look like brand new... I was also able to measure my rotor-to-housing clearances with Feeler Gauges, with an average of .004" of clearance. Carry on.