Z-version upgrade fails to find local repositories - why?

I have a Satellite running 6.8.2 and I would like to update to 6.8.4. This is a disconnected Satellite.

satellite-maintain upgrade check --target-version 6.8.z complains that none of the required repositories are enabled.

The update guide for disconnected satellite has you sync a set of repos with immediate download policy, then disable them and create a local configuration file. I noticed that when disabling the RH repos, the pulp published directories are removed, which makes the provided config file invalid.

If I try setting up all local repositories (i.e. by using ISOs and/or manually pointing to the sat-import directory for the respective repos) then yum repolist is successful and shows available packages but satellite-maintain fails as above.

Where am I going awry? Thanks!