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.
This is something I've been writing about for some time, and Microsoft has today confirmed that this is indeed something that will ship with Windows 10X. This is possible thanks to how Windows 10X is installed on devices, using OS state seperation which keeps the actual OS seperated from app files, and user files. Similar to Android and Chrome OS, Windows 10X will install feature updates to an offline partition, and simply switch to that partition when the update is done installing.
That's how Microsoft is able to achieve feature updates that install so quickly. This should reduce device downtime when a feature update is made available, and could even pave the way to a world where "feature updates" are treated just like any other update, and come more frequently as a result.