Do I need a Samsung display to test the Samsung VXT?
No, you don't have to buy a Samsung Signage display to test Samsung VXT. You can simply create a virtual display in VXT, pair it with the system and test the results without a display on any device that supports a Chrome browser. Even a tablet or smartphone can become a virtual display.
If you have a TV or display with the Android operating system, or a Windows PC that you can connect to a display, you can always install the free VXT player on these devices and thus connect a device to VXT.