So it seems to be an open issue now. So I guess until this is done I will have to rely on .NET Core API reference and pray I won\'t hit one of the 43 API
There is a fine web page maintained by a PM for the BCL (Immo Landwerth). It shows all APIs, their current implementations in all imaginable platforms (.NET Framework, .NET Core, UWP, Mono, ...) and their status in the .NET Standard Versions including the plan for 2.0.
http://apisof.net (sample for List)
Hope that helps. The fact that the standard based library may throw in certain edge cases is unfortunate. I guess there will be some tooling around it.
Delta between 1.4 and 1.5: https://github.com/dotnet/standard/blob/master/docs/versions/netstandard1.5_diff.md
Delta between 1.5 and 1.6: https://github.com/dotnet/standard/blob/master/docs/versions/netstandard1.6_diff.md
Do not worry so much about the 4.6 vs 4.6.2 issue. When I remember right they will address this issue.
About the concern regards drawing: indeed the most annoying problem. System.Drawing is based on GDI and therefore not available everywhere. There are alternatives for common task. Do not forget, that most rendering is client stuff and therefore not exactly a use case of the standard but more of an concrete app model.