Getting Spaces and their order for each display

watch_spaces.swift

var observer: Observer!
func stuff() {
    guard let database = UserDefaults.init(suiteName: "com.apple.spaces") else {
        fatalError("cannot read spaces data")
    }
    print(String(describing: database.object(forKey: "SpacesDisplayConfiguration")))
    observer = Observer(object: database)
}

class Observer: NSObject {
    @objc var database: UserDefaults
    var observation: NSKeyValueObservation?

    init(object: UserDefaults) {
        database = object
        super.init()

        database.addObserver(self, forKeyPath: "SpacesDisplayConfiguration", options: [.new, .old,
            .initial], context: nil);
    }

    override func observeValue(forKeyPath: String?, of object: Any?, change: [NSKeyValueChangeKey:
        Any]?, context: UnsafeMutableRawPointer?) {
        print("changed")
    }
}

Do you know if the "app-bindings key updates its values when a user right-clicks on an application's Dock icon and changes the "Assign to" options?

For example, does changing options from None to All Desktops update the app-Bindings values?

Off the top of my head I don't know, but it seems plausible that it would.

Mostly I've just had to experiment with little programs and find out what happens. (Which isn't great for backwards/forwards compatibility, but not much else you can do.)