if I'm understanding it right then currently are default dependencies composite site contains all the additional 3rd party plugins we are testing even if there are zero dependencies on it.
We really shouldn't be providing an updatesite for JBT with anything beyond the bare minimum to simple keep updates fast and simple.
Having a seperate site we can use for basic testing and mirroring is fine - but adding it as default and thus make it a "supported" url really should not be happening