It seems that Substance materials usually start as Legacy shaders. Often when selecting the Standard shader Unity will get hung up.
I imagine this’ll be fixed in later builds.
I’m not sure I understand what you mean.
In Substance Designer you can select the type of shader you want to create for. This makes Desginer create standard outputs for this soft of preset and also sets the standard preview shader to one that works with the settings.
This has not much to do with Unity thoug. In unity you only use the textures or the substance files to create textures within Unity procedurally. These files still work with Unity’s own shaders.
I never encountered a crash in this regard so far.