Set a device as corporate/personal from the console or AD using AD Writeback.
Currently a device needs to be pre-enrolled by IMEI/Serial or enrolled by a Device Enrollment Manager to be a corporate device. As this is just a flag in Intune, we should be able to toggle Corporate/Personal after enrollment. Preferably via some sort of API, but possibly through AADConnect/AD.
AFAIK, if a user enrolls with his AAD creds during OOBE and runs Win10 Enterprise, then the device is flagged automatically as "Corporate" : https://docs.microsoft.com/en-us/intune/corporate-identifiers-add (I did the test and it works).
And you can toggle manually anyway later between Corp and Personal in the Intune Ibiza-style interface.
So no need to play with any IMEI or DEM :-).
Scott Breen commented
1) the ability to toggle this in the console like you can for devices in Configuration Manager hybrid.
2) Ability to do this for Windows 10 "mobile" devices (Home, Pro, Enterprise, Education)