The mode that Windows Time uses to send requests is set by the following registry subkey: 

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\TimeProviders\NtpServer
If the value of the Enabled entry in this subkey is 1, Windows Time uses symmetric active mode. Otherwise, Windows Time uses client mode.

The 0x8 setting that is referenced in the command in the "Resolution" section sets Windows Time to use client mode.

The valid settings for the mode used with the /manualpeerlist switch include the following: •0x01 - use special poll interval SpecialInterval 
•0x02 - UseAsFallbackOnly 
•0x04 - send request as SymmetricActive mode
•0x08 - send request as Client mode