If set to SyncConfirmOverwrite=0 the confirmation is off. But this is - in general - dangerous.
So it would be a good new option to store this feature separately for each 'saved sync directories + options' like all the other specific options.
Joube
See:
Voreinstellungen bei Synchronisation möglich ?
preventing display of messages when synchronizing files
And:
HISTORY.TXT wrote: 09.02.16 Added: Disable overwrite confirmation in sync: wincmd.ini [Confirmation] SyncConfirmOverwrite=0 (32/64)