Nice!
Maybe those are only EU868? I also see 178 EUIs starting with eui-00001c497b
.
Many of those are registered for EU868 as well, but maybe they’re really US915 devices configured for EU868 in TTN Console. (I don’t know how many people got the US915 device when the EU868 was no longer available at the conference.) The EUI surely determines the frequency plan/configuration, so multiple ranges might be expected:
…though it seems the above might only apply to receiving uplinks, as settings in TTN Console affect the frequency for Join Accept downlinks. At least those that are displayed in TTN Console, for a US915 device configured for EU868: