Some of us (including me) have had good luck with the Motive pressure bleeder system, the universal plate works on the dual masters, many of us use ‘c’clamps instead of the chains. Available at Summit Racing and other large suppliers.
First step with it is to pressurize the system for 5 minutes or more to 15psi with fluid in the res and lines but without fluid in the Motive, this is to confirm there are no leaks, then release, add fluid to the Motive tank, pressurize it again, and bleed away.
Worked great on mine with 1” bore dual master under floor, residual psi devices front and rear, and drums on all 4 corners. I too had no luck with a vacuum bleeder….
Btw: Some play in the pedal adjustment is needed to confirm the master is getting to the beginning of travel to grab fluid to push…..
Good luck….
