annv As I understand it Amulet HotKey make enterprise-grade workstations and virtualisation services. They are associated with Teradici (who I believe invented or patented PCoIP).
Basically in order for that dithering kext to work, it performs a check to ensure that Amulet hardware of some form (extender cards, graphics cards, workstation) is connected. If we could get hold of the kext there may be a way to reverse-engineer it, however there is no public link (that we know of). Also trying to get it through Amulet resellers has not worked, so the only other way would be through AHK's own support channel (but you have to prove via serial number etc that you own one of their products).
Looking on eBay I think the basic KVM cards are in the range of $400-600
The one positive thing about all this is it shows there are legitimate needs to disable dithering. With temporal dithering enabled (by default) on AppleOS, as PCoIP transmits the pixel data, there is a much higher bandwidth usage with dithering enabled so to save resources and stop the virtual sessions from failing, users require dithering to be disabled.