But as stated here :
Allow reboot - This option applies to Windows operating systems only and forces the client computer to reboot once the updates are installed. If this option is not selected, updates that require a reboot will not be installed.
So in the current implementation, the scenario you want to achieve is not possible. You either install all updates and if one of them requires to reboot the computer will reboot. Or you install all updates that do not require a reboot.
The only workaround for this can be to schedule the task in a timeframe when the reboot will not cause any problems.