ive watched the video and read the replies but im still not sure what it is youre trying to do. Are you trying to set up the hoykeys for switching, or are you trying to get one specific view mode?
Add a cube
Make it editable (press C)
Add an SDS
Set viewport subdivisions to 3 or 4
Put the cube inside the SDS
Select polygon mode
Thats it. You should now have a low poly cube cage with a smooth model model inside. If you want to add the isoline overlay, select Display > Quick shading (lines). And then select Display > Isoparms.
Interesting observation. I had not noticed this, and the difference between values, though exceptionally small, probably shouldn't be there.
I shall hold speculation / reporting for now as one of the Maxon guys might be able to jump in here and explain...
CBR