If you would have asked before posting, I would have explained that what you are seeing is exactly one of the process changes that results in lower variability.
As explained previously, JK Products Retro 7R and 7 motors are now 100% robotically computer balanced. They are the only motors in the industry that are 100% computer balanced. This is an internal processing/tolerance change, not a major product specification change. The IRRA® board was informed of this process improvement and other process tolerance improvements, all designed to reduce variability and make our motors the most consistent motors in the industry.
In the past, all our armatures were hand balanced, like some of our competitors. As you can imagine, this hand balancing was not nearly as consistent as an automated machine can be. Not only that, the automatic balancing can balance to a much tighter tolerance using much smaller corrections than are available using hand balancing. That is what you are seeing in your photograph. Notching for larger changes, and very small drill holes for even better balancing than ever before.
I will have a detailed balancing post on our Facebook page later today, including a video of the process that you might find interesting.
Finally, if anyone thinks they have found a problem with any of our products, please grant me the courtesy of contacting me first by email; I will always respond. If I don’t satisfy your concerns, feel free then to express them on social media.