Windows 10X will only require a short reboot when installing feature updates.
At Microsoft's 365 Developer Day, the company has confirmed that Windows 10X will feature faster Windows Update experiences that should keep full feature updates to under 90 seconds when requiring a reboot. This is a huge improvement over Windows 10, which can take anywhere from 5-20 minutes to install a feature update once it's ready to reboot.
Full story from the WindowsCentral blog...