Hello,
I am experiencing the issue with Windows 10 1607 in Windows PE with cmdlets Clear-Disk and New-Partition, at least. Those cmdlets just do nothing and produce no error message from within WinPE
This issue is being discussed here as well:
https://social.technet.microsoft.com/Forums/windowsserver/en-US/3a0e7e9c-f1ea-4324-8a17-f4c447efcbb0/some-storage-cmdlets-do-not-work-under-winpe?forum=winserverpowershell