They could just be logging IPs that have been used by a large number of accounts. They could also be tracking accounts that tend to hop between IPs and enforce more strictly on them.
Already did it, got lifetime emby premiere license, can watch whatever I want wherever I am, the ease of use and the low price were charming at the start, but I guess it was too good to last
the Kodi plugin, emby integrates itself by reusing existing elements, including the Kodi player and Kodi libraries so you can scroll in movies both local files and emby files and use the same flow regardless, Plex last time I tried it, had a full blown view on top of Kodi which was detached from the system, so you either go full Plex or it's not a nice experience
EDIT: Oops replied to wrong comment.