I have custom control which using .NET Standard 1.0. Recently faced the Xaml previewer issue in VS2019 and to make the control visible in the designer, need to set [DesignTimeVisible (true)] attribute for control. But, DesignTimeVisible attribute is not available in .NET Standard 1.0 and have plans to move control to .NET Standard 2.0. Also, I have doubts why Xamarin.Forms provide support for both .NET Standard 1 & 2 rather than .NET Standard 2? If I move my control to .NET Standard 2.0 whether I will face any compatibility issue?