There are few issues with hidden tags (e.g. discussiontools-source-enhanced)
- You can't search for them, or event manually type them in to the search box on RecentChanges
- You can access a list of associated changes via Special:Tags, e.g. https://en.wikipedia.beta.wmflabs.org/wiki/Special:Tags will take me to https://en.wikipedia.beta.wmflabs.org/w/index.php?title=Special:RecentChanges&tagfilter=discussiontools-source-enhanced, however:
- As soon as you land on Special:RecentChanges, the URL gets rewritten, removing the tagfilter parameter