Automated method to invoke Gnome software update / reboot

I manage a number of Fedora desktops workstations. I like the Gnome Software download updates / reboot into offline update (which looks better in Fedora 30 BTW) / reboot into updated system. This works great via the GUI, but I would like an command line method I could use in a playbook to trigger this process.

To be clear, I’m talking about same version updates, not upgrades between releases. Command line version upgrades work great (dnf system-upgrade), but I can’t find a similar method for updates.

On my test system dnf and the Software GUI show updates available, but
sudo pkcon --only-download update returns
"There are no updates available at this time."
BUT: pkcon offline-get-prepared does list the updates.
/usr/libexec/pk-trigger-offline-update doesn’t exist.
The similar pkexec /usr/libexec/pk-offline-update doesn’t do anything.
Neither does pkcon offline-trigger which seems to be exactly what I want per the man page.