No Reboot on upgrade
The installer can currently cause a reboot on upgrade in the automatic upgrade, the Windows Installer recognizes the device needs a reboot so it reboots even if Screenconnect doesn't require it. (MSI REBOOT=REALLYSUPPRESS) This issue caused servers to reboot during business hours.
I had critical analysis workstations get rebooted during the middle of a monthlong job that was analyzing data for Nuclear Powerplants. Needless to say, starting over after it had been running for two weeks did not make management happy.