I know DB and Overdrive have different implementations of VDCP since they don't share the same code in the backed. But they will be very similar. I don't know whether one is more "developed" than the other .
As for troubleshooting, I would use WireShark to monitor the communication coming from both Overdrive and DashBoard to see what the differences are when sending commands (and what is sent back).
#DashBoard