I've blocked MSA via group policies but there are still remnants in the OS. What packages are responsible for this? Microsoft Account service had to come from somewhere. I'm 3/4 of the way to a fully cleaned os. CRL, SPP, settings app and updates are the last things left phoning home.
Make you ISO cut with MSMG Toolkit. Delete the Support App in the "Windows Komponenten" https://forums.mydigitallife.net/threads/50572-MSMG-ToolKit
I have no support app in MSMG. Its not even an option. The only 2 apps installed are the control panel and shell experience.