Working here. I’ve checked the rss.xml file in a validator and it passes. Anyway, I’ve re-exported & uplaoded the RSS and Atom feeds. The JSON feed can’t be properly completed pending a feature request for tweaks to some action/export code.
Edit: meant to add, very happy spomeone actually uses these feeds. I build them mainly to learn the technique and give a working model for others (in the TBX’s templates).