So there is work scheduled to add IDE support for choosing the target framework version for XM Full projects.
I’ve thought about just bumping it up to 4.6.1 or higher, it’d likely just be a one line change here:
xamarin-macios - Bridges the worlds of .NET with the native APIs of Mac, iOS, tvOS, and watchOS.
however I am concerned about backwards compatibility. What if an application depends on a nuget with a 4.5 and 4.6 variant, and my change caused a new one to be chosen and that broke things on upgrade (in a hard to debug way).
Xamarin.Mac has reasonably high backwards compatibility requirements.