The experience of Remote Desktop in Surface Pro 4 are terrible when using Microsoft Remote Desktop (RDP) as the front and icon are very small and hard to see.
Finally, I manage to find Loyal TS which is a freeware, and bring the RDP experience in Windows 10 running on Surface Pro 4 back to normal by using 1280 x 720 Desktop size
Strongly recommend for all Surface Pro users who is using RDP heavily.
Reference link
1. https://www.royalapplications.com/ts/win/features