Is this not smaller than a 660,
Good question? I looked at this sometime ago but have never actually seen one?
The WunderLINQ itself is just the device that plugs into the BMW Sat Nav Cradle. On the GS/RT/XR etc this is on the outside of the bike so the depth of the setup isn't an issue. On the K1600 you have to push a button on the dash that raises the screen and then pops the top of the dashboard up and the cradle raises up for access. When you put the Nav into the cradle and push it back down it locks and seals up behind the dashboard cutout, so that exact depth is important, and the cutout is exactly the right size for the Nav (this has changed over the years for Nav 4/5/6). If the mount is too large you wont be able to shut the dashboard down, and if it is too small it will be sunken in, and then you would need a phone with the same size screen to view the details on it OK.
You would also have to insert/connect and remove/disconnect it whenever you wanted your phone which would be a pain:
https://youtu.be/Th2Mp7VjtUQIf you could find a phone mount exactly the right size and modify the aperture on the dashboard it might work
** Edit ** Just found this - you could just feed the cable out to it I suppose and sit it outside the dashboard?