Hi Kendy,
Posted this on your Facebook page today :
Good luck with the GPD Win, looks like a great concept.
A few tips to help you succeed :
Show the windows interface in your renders with font/icon scaling enabled and set at perhaps 200% it will then look (and be) usable on a device with a small capacitive display.
Get some gameplay footage up using your prototype ASAP, showing things like Skyrim & PC Minecraft running on a handheld will generate some interest...
Many PC games use mouse & keyboard, when selecting mouse mode make both joysticks act as the mouse (for left and right handers) and give users the option of using / configuring the other buttons & controls. I for one would configure the DPAD as WSAD, the gaming buttons could be set for Jump, Run, Crouch, Inventory etc.
See if you can make SteamOS an option on boot, a dedicated handheld steam machine would turn a few heads.