Looks like I'll be answering my own question. That's fine, hopefully it helps someone else.
I bought a mount, threw a Cmore on it, figured out quickly that I really like the optic positioned like that, and bought two more 90° mounts. One for a Ruger mkIII and the other sits atop the Cmore "railway" mount making it a much lower sight picture than the typical upright mounting on a picatinny rail. It also mounts 90° on the ADM QD Cmore mount, which is nice.
Quick review, sighting in reminded me of organic chemistry... You've got to visualize and think differently. Luckily there's rotation engravings on the mount. Once sighted in, the Cmore works just as anyone would expect except that the sight picture is much lower. I like it, it's like having a big piece of glass to look through right above the receiver/action. The downside is funky sighting in as it's now rotated 90°, and there is a bit of weight to the left side of the Ruger pistol that was noticeable at first. I've gotten used to the balance now and it doesn't bother me.
Cmore sights aren't for everybody, but for gun games they're really really fast compared to other options. I personally wouldn't use nor recommend a Cmore for anything outside run/gun, steel challenge, or a range toy. But if you're already using a Cmore you might want to check out the Striplin 90° mounts, it's a pretty sweet set up.
Pictures later this week.