Back in November, 2014, I reported to Microsoft that mandatory profiles were broken. Mandatory profiles were actually broken in Windows 8.1 as well if you used the official CopyProfile method, although the effects were slightly less noticeable. It still wasn't kosher to deploy in a production environment like that.
I have reported these issues in Microsoft's Windows 10 Feedback app and in the Windows 10 UserVoice website. I have done this, again, since November, 2014.
Nothing has changed.
Microsoft gives not two damns about enterprise or education. If they'd acknowledge these issues, I might have less heartburn, but I'm not sure they are even on Microsoft's radar. Windows 8 had these issues for the entire time the operating system was mainstream, and Microsoft did not so much as wink to IT professionals that they were issues.
I really wonder if mandatory profiles are even officially supported, anymore. Where is the (recent) documentation on how to properly, officially create them? Good luck finding it. I'd be surprised if current Microsoft programmers/engineers even know that mandatory profiles are a "thing." The folks that worked on mandatory profiles in Windows 7 are probably long gone.