Dual displays using gert vga 666 adapter and hdmi output

Question

My company is looking into replacing all of our old wyse thin clients, with raspberry pi's. This works fantastic for the people who only use one display. To try and make it work for people with dual displays, I purchased the gert vga 666 kit. I can get either the vga display to work, or the hdmi, but not both at the same time. Has anyone been able to get this to work? If so what do I need to add to my config.txt to make this work?

Thank you, Brendan