Exactly the sort of quirk I was concerned about! That is why I will just keep making updates as I learn of new discoveries. I have no doubt that anyone savvy enough to get a Magic Box and run SignalCheck will immediately notice if the app is not correct, and word always seems to get back to me.
Thank you @UPdownLoAD and @bucdenny! I will add 0F0. Looks like it will be tricky staying on top of the MB GCI's.. they are burning through prefixes fairly quickly early on, at this rate they will be at 0FF in no time. It would be easier for me to assume everything between 0EC and 0FF will be a MB but I'm not ready to do that yet.
Also, thank you to those of you who have been providing me with diagnostic reports and feedback about the Wi-Fi channel issue. I'm still working on finishing up overhauling that, but it looks like the "new" method does reliably identify DFS channels on newer devices.