I stopped reading when he said "Windows"
Too niche a Smartphone platform.
Like testing the possibility of running business on an OS/2 Laptop rather than NT4.0 or Win95 instead of the VAX (or AS/400 or Netware Server), back in 1996.
The only valid test is to use the most popular platform, Android. With about a 4" screen.
Using WinPhone smacks of MS Marketing even if it's the best Solution. An iPhone smacks of cosying up to a one trick pony. How many companies make iPhones? A least a few different people make Winphones, still.
Biting the hand that feeds IT
