Updated regkey to v5. Should work with more SB models now:
Surface Book and Surface Pro 4 - high-dpi multi-monitor optimization regkey for alternate 3:2 aspect ratio resolutions - danchar - Site Home - MSDN Blogs
If v4 did not work for you on SB, please try this new key and let me know the result.
Link is no longer valid. Do you have this anywhere else by chance? Thanks much!