So the thing with the 507 is that it can indicate that he went hypoglycemic during the cycle. The liver then dumps a bunch of glucose to bring the number back into safe ranges which can result in unusually high numbers. We call it a bounce. Of course, it can also be an indication that there isn't enough insulin. So that's why we ask for the mid-cycle numbers. It's the only way to tell if he's getting too much, too little, or the right amount of insulin.
As for the ears, it's only two ears, but you can rotate the location. I test both the front edge and back edge of both ears, so that's 4, and even within a given side, I rotate between top, middle, and bottom of the "sweet spot."
Food: how is Reegan's weight? If he's underweight, I would recommend feeding him as much as he wants right now. He likely will be asking for more food than normal because unregulated blood glucose means that they can't use the nutrients from the food as efficiently as a healthy cat - so they are literally starving, not just being dramatic or demanding as cats can be sometimes

- he really does need more food than normal. Of course if he's overweight, that's a different story. You might also consider spreading the food out during the day if your schedule allows. Diabetic cats (similar to people) benefit from having multiple snacks during the day to help them keep a steadier BG level instead of dramatic dives and spikes in numbers.
Many cats will reach regulation better if they get the food they need during the process. If he doesn't get enough calories for his needs right now, you increase the risk of developing ketones which can be very dangerous very quickly in a cat.
Just a second and I'll make another post with some other treat options...