RDP Resolution and scaling

I'm having trouble getting an acceptable rdp resolution on the mac using version 5.1.0.0 (and earlier).
I've tried a lot of different setting (resolution, scaled, sizing mode, undocked, etc) and combination of settings, but it comes nowhere near the the default "Native" + "Scale" setting of the Microsoft RDP client for mac - that client just works.
It feels like there is a "High-RES" setting missing in the native client.

Anyone have similar problems or a solution for the issue?

I'm running on a 2017 macbook pro with macOS 10.13.3

attached is a screenshot of a typical setting - all combinations are more or less the same.