Jetpack Compose nested navigation with shared route using wrong default args (addInDefaultArgs)

Question

The following code has 2 nav graphs and a shared nested route.

One of the nav graphs requires a user ID argument. The other does not. I can't navigate to the other one without supplying a user ID. Why is that and what is the best approach to take here.

class MainActivity : ComponentActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContent {
            NestedNavigationGraphsGuideTheme {
                val navController = rememberNavController()
                NavHost(
                    navController = navController,
                    startDestination = "foo"
                ) {
                    navigation(
                        route = "foo",
                        startDestination = "screen_1",
                    ) {
                        composable("screen_1") {
                            Column {
                                Text(text = "SCREEN 1")

                                Button(
                                    onClick = {
                                        navController.navigate("bar?$userIdArg=9999")
                                    }) {
                                    Text(text = "GO TO BAR GRAPH (SCREEN 2)")
                                }

                                Button(
                                    onClick = {
                                        navController.navigateToEmployeePin(path = "from_screen_1")
                                    }) {
                                    Text(text = "GO TO EMPLOYEE PIN FROM FOO GRAPH")
                                }
                            }
                        }
                        composable(
                            route = EMPLOYEE_PIN_ROUTE,
                            arguments = listOf(
                                navArgument(pathArg) {
                                    type = NavType.StringType
                                },
                            )
                        ) {
                            // we can't load this screen, it's expecting a userIdArg which is
                            // completely irrelevant to this composable
                            Text(text = "EMPLOYEE PIN ROUTE, WITHIN FOO GRAPH")
                        }

                    }
                    navigation(
                        route = "bar?$userIdArg={$userIdArg}",
                        startDestination = "screen_2",
                        arguments = listOf(
                            navArgument(userIdArg) {
                                type = NavType.IntType
                            },
                        )
                    ) {
                        composable("screen_2") {
                            Text(text = "SCREEN 2")

                            Button(
                                onClick = {
                                    navController.navigateToEmployeePin(path = "from_screen_2")
                                }) {
                                Text(text = "GO TO EMPLOYEE PIN FROM BAR GRAPH")
                            }

                        }
                        composable(
                            route = EMPLOYEE_PIN_ROUTE,
                            arguments = listOf(
                                navArgument(pathArg) {
                                    type = NavType.StringType
                                },
                            )
                        ) {
                            Text(text = "EMPLOYEE PIN SCREEN (WITHIN BAR GRAPH)")
                        }
                    }
                }
            }
        }
    }
}

const val userIdArg = "userId"
const val pathArg = "path"
const val EMPLOYEE_PIN_ROUTE = "employee_pin_route/{$pathArg}"
fun NavController.navigateToEmployeePin(
    navOptions: NavOptions? = null,
    path: String,
) {

    this.navigate(
        EMPLOYEE_PIN_ROUTE.replace("{$pathArg}", path),
        navOptions
    )
}