v9: Enable automatic updates via registry?

I need to update a bunch of TeamViewer hosts running v9 to the latest version. I was hoping to just turn on automatic updates and let TeamViewer update itself within a week. Originally, I was hoping to use the TeamViewer's Policy management feature to push out a config change to enable weekly checks and to set "install new versions automatically" to All Versions. TeamViewer 9 doesn't support policies. Now I'm looking for alternatives.

My next option was to tweak registry settings (all the clients are Windows machines). I found: HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\TeamViewer\Version9\AutoUpdateMode which seems to correspond to the "Install new versions automatically" configuration option. I don't see a registry entry to change the "Check for new version" option. Does that option not exist or am I just missing it?

Anyone else have recommendation for the best way to get a bunch of TeamViewer 9 clients updated to 15? We do have the ability to run scripts on the clients, which I was hoping to use to tweak the registry and restart TeamViewer. I guess my final automated option would be to push a script that uninstalls 9 and then installs 15 via MSI.