Is it possible to just have wrappers for GNUStep API instead of the approach Apple takes where they expose Obj-C methods and classes as first class methods and classes in Swift through modifications to their ObjC API/Runtime and special interop code in the Apple Swift runtime, we instead could interact with the GNUStep API as if it were C (it all really is just C when complied, right?) We could instead write wrappers around it all. Maybe having a root GNUStepObjC object which handles calling method into the Obj-C runtime? I am not even sure if that is possible, but I would really enjoy seeing if someone could attempt it.
Maybe this could be done in a similar fashion as GitHub - rhx/SwiftGtk: A Swift wrapper around gtk-3.x and gtk-4.x that is largely auto-generated from gobject-introspection
It would make code that is not fully compatible with targets to Apple's ObjC runtime, but might yield at least some results today.
This is one area that I am not fully versed enough to try it my self.
But if GNUStep had Swift support, I would be making so many apps for it.