OK, I've just had reason to try restoring a Windows 10 system drive backup, and though I unlocked the destination system partition in WinRE, it restored unencrypted. Reviewing the KB article, I think this is what messed me up:https://www.terabyteunlimited.com/kb/article.php?id=616
"Restoring an entire disk Type A backup image (e.g. a backup of the Windows disk taken using VSS) will result in the restored partition not being encrypted even if the encrypted destination partition was unlocked. You would need to enable BitLocker on the partition to encrypt it."
My question now is, should I have just restored "MBR 1" instead of the entire drive, which includes "System Reserved"? I have no idea what Windows does with System Reserved, so to be safe, it never occurred to me NOT to restore it. However, I just wanted to revert some ordinary application-level changes that didn't work out.