I recall the Pentax GPS unit that clipped onto the hot shoe of my 645Z was fast and accurate when out shooting landscapes. I found it extremely helpful for locating exactly where I had shot an image or series of captures.
If Fuji is serious about encouraging landscape photographers to buy and use the GFX in the field, where one often finds himself in remote areas, then they should start developing a clip-on GPS unit sooner than later. Otherwise most landscape photographers might feel left out and view the GFX as mainly a studio camera and instead buy the X1D.