I have NO secrets. I will gladly share how I do "anything" with the group..
1- Install in Virtualbox (using VHD) and go thru ALL the motions like you were installing to a regular hard drive for yourself.
2- When it gets to the NAME & Password, I choose a NAME and NO PASSWORD so it auto logs in.
3- I do ALL updates
4- I install ALL programs I want.
5- Disc Clean and clear out ALL the old stuff, like older updates, temp files, etc...
6- When done, just shut down the VM like you were logging off for the night and shutting PC down.
7- Mount the VM with VHD attatch or similar, THEN use DISM++ to capture the WIM.
8- Replace the WIM in an OEM version with the NEW WIM and bingo, you have an OS that auto logs in with given name, without a password, and ALL the customisations ready to go, with an updated system.
9- To modify login credentials, just like any other version, just hit START, then type in NETPLWIZ, and do your stuff
10- Install process goes from 20 min to about 5-10 min TOTAL! MUCH faster installs with NONE of the stupid questions.
NOTE: I always do "Limited Experience" for account, so I DONT have to use a microsoft account. I would think if you built a version like this WITH a microsoft account, then your account would be shared with the world. Not my idea of fun