> from the main page of my Miniflux instance, and then put /feeds on the end
This case is relative to a single baseURL. The poster was proposing to have a bookmark relative to the URL you're currently browsing from, so that you could click "/feeds" from any Miniflux instance you're currently visiting.
This case is relative to a single baseURL. The poster was proposing to have a bookmark relative to the URL you're currently browsing from, so that you could click "/feeds" from any Miniflux instance you're currently visiting.