With the assistance of a helpful individual (kmbanana) on the Emby discord, I was able to get Emby for Roku working--   for those that have struggled previously, if you have Emby installed behind a reverse proxy to go to something like https://domain.com/emby (as opposed to https://emby.domain.com) this apparently completely breaks Emby for Roku when connecting via Emby Connect.  It'll see the server and on the "connect to a server" screen on Emby for Roku it'll says the url is "https://domain