Those buttons are not HID based. They require a driver. Usually that driver is built into Windows, so you don't see it install. Regular RDP cannot tunnel USB devices that are not HID. HID devices, like mouse and keyboard, are directed into the remote session, but the extra buttons aren't. You will need a USB tunnel for that. Wyse TCX USB will provide this. Some desktop brokers also have a USB tunnel, like Citrix HDX Plug and Play.
The next thing you might say is, your USB thumb drive works and the USB printer works, but those things are mapped, not installed. Try a flat bed scanner or a multimedia Keyboard will all its buttons. Those things require a driver and must be installed. They will need a USB tunnel. Hope this helps.
Thanks makes sense.
Do you think we will get support when Wyse support RDP 7.1/RemoteFX?