I don’t know if you have solved this, but this is something I already do.
Get the Blackmagic ‘Intensity Pro’ HDMI input card for your Mac Pro (Make sure you switch of Skype when running it! that issue drove me crazy!) https://www.blackmagic-design.com/products/intensity/models/ You can pick up this card for a little over £100
Plug your Z7’s HDMI output the the Intensity Pro’s input…
job done.