Further testing on Number of outputs from the New Pro pro reveals that you can only get 3 outputs with a combination of DVI and HDMI. Apparently by using dual link DVI cables there will be more outputs available. I have ordered 4 dual links to see what can occur. You can connect 6 thunderbolt monitors - however not much use to us.
We also found that HDCP can be implemented on some switches - we found injecting a Parrot into the chain solved that HDCP problem.
I will let you all know the outcome of the Dual Link DVI testing.
Michael