WHHL is more protective.
WDAC will block the same executables blocked by SAC.
Hardening (including SRP) will block all file types blocked by SAC, and even more, with the advantage that it cannot be bypassed by removing MoTW (manaully, by malware, or by usb memory transfer).
In my case, I had to set two values:
VerifiedAndReputableIgnoreAutoOptOut ---> 1
VerifiedAndReputablePolicyState ---> 1
Even after the update, I still cannot set SAC ON via Security Center. But I like this behavior over the expected one.
I have enabled sending the optional diagnostic data:
Me too; I thought, after update, it will be enabled and disabled from the security center without tinkering with registry editor.
Anyway, I haved disabled it again and back to WHHL.