Loving the Custom Channels feature! I am using it a lot now for music, live streamers I've found, webcams around the world, etc.
I've added these as separate sources of Custom Channels to keep things organized, so I have "Music Streams," "Webcams," etc. alongside FuboTV and PlayOn Cloud, etc. as sources. This also allows me keep their channel number sequencing distinct. This content has no XML Guide data of course, and I'm fine with that, they are just airing the same content 24/7 and don't really need an EPG.
Anyway, minor issue, but worth mentioning, when I am in the Guide in the web admin page, and I filter to one of these EPG-less custom channel sources, that has no XMLTV guide data, the channels listed are from ALL of these sources. There appears no way for me to filter down to just one of them. This feels like a bug.