As part of .NET 6 migration existing types that are not compatible or serve for exactly the same purpose should be removed or at least deprecated to allow Xamarin SDK to work with all .NET libraries.

nint/nuint types

These types in Xamarin have a bit different semantic than in C# and I think the best approach would be to remove them from public API. I didn't try what happens when C# compiler see them defined as types but they should certainly not be prefered types over C# built-in version.

CLong/CULong/NFloat types

The existing types which serve exactly the same needs should be deprecated to allow easier sharing for .NET libraries.

Time estimate: depends on what we decide to do. Worst case is probably ~4 weeks to remove the Xamarin types and deal with the fallout, best case is no time at all if we decide to do nothing.