I have no result found from Google regarding Designsync dword and i think i should share it out after getting the info from Designsync support.
Command:
grep -H ServerMaintenanceMode=dword:1 /<path>/<port_number>/PortRegistry.reg
dword:1 = Normal operation
dword:2 = Set server to read-only mode
dword:3 = block all read and write access to server

I missed what the question was. I know a bit about DesignSync. Maybe I can help. Send me a message.
Rick
Hi Rick,
I was just writing this down for my future references. it is merely impossible to find any designsync related document in google
thanks for your offer !