A change to support macOS just barely missed the snap to get in .NET 7 but has been available since early pre-preview builds of .NET 8. Its support is really good in 8 and there will be even a feature to use NativeAOT for 'net8.0-ios' targets meaning you could write components in C# and integrate them into Swift binaries via C bindings (maybe there are better interop options? my knowledge is very limited on this topic).