Odd. In a fit of experimentation i set Systemui to start on boot, and notice that MCE defaults to ignoring the power button after a reboot even tho i had it set to menu before rebooting. This tho via ASUI-settings so i do not know how reliable a info source it is. This in particular as a MCE restart results in Systemui working even tho the setting reads ignore in ASUI-settings.

Edit: Bah, in 1 of 3 reboots after enabling Systemui, MCE behaved itself. But after the 4th it does not.