Hi vadm168,
Sorry about that. Not sure what was going on with my Update Manager but you are right.
A Host Upgrade doesn't appear to allow for the staging to happen and the option for Staging is greyed out if this is the only baseline attached to the host. However if you upload the "Offline Bundle" to do the host upgrade (though this is considered a Host Patch) then you can stage this. Guess it makes sense as the button is "Stage Patches" not "Stage Patches and Updates"
I'm just testing whether you can have another Host Patch associated to the host whether this would stage the Host Update as well. The option is not greyed out but this doesn't mean that clicking it would also stage the Host Update. Will report back here with findings.
Kind regards.