FWIW... It would be nice if somehow (and I don't know if this is possible) you could schedule MC to apply any pending updates at 2am every Wednesday, or something like that. And have it completely automated.
You could just script MC to close and then to restart itself, which would run any pending installers. But the issue is the UAC prompt, which won't approve itself, and if it needs to reboot it waits at the click next to reboot screen (and for reasons I still haven't figured out, my HTPC again still needs to reboot essentially 100% of the time).
So... I agree it isn't 100% ideal. I have quite a few different installs spread around on machines I only occasionally touch, and they often get way out of date.