"DP won't respond to MMC messages, BUT you can set DP & the D8B to slave to MTC from the MTPAV and send MMC to it. Leave the MTPAV in internal mode. Set DP to send MMC to the MTPAV (MMC window) and slave to MTC from the MTPIAV (basics menu>receive sync). Or choose sample accurate sync here if you have a 9pin
connection in the PCI324 card.

Make bidirectional MIDI connections between the D8B and a port on the MTPAV.

Configure a D8B in Freemidi on that port.

In clockworks, make a cable routing from the midi input of the D8B in the left hand column to"MMC in" in the right hand column. Make
cable routing from "MTC out" in the left hand column to the output the D8B is connected to, in the right hand column.

Set the D8B to send MMC and slave to MTC.

Now hitting play on either DP or the D8B will make the other roll, since they're both slaved to the MTPAV!