Flutter GoRouter deep links how to change the Gorouter of a context

Question

I'm building a large application that will need a deep links, I choose GoRouter to implement the routing system but found all the examples and tutorials about deep links very simple none of them describe a routing system of large application. I want to create a few GoRouter instances for example:

static GoRouter onBoardingRouter(AuthState authState) => GoRouter(
        initialLocation: "/logIn",
        navigatorKey: onBoardingNavigatorKey,
        routes: [
          GoRoute(
            name: "login",
            path: "/logIn",
            builder: (context, state) => const LoginPage(),
            //Example of redirection        
            redirect: (context, state) => authState == AuthState.loading ? "/splash" : null,
          ),
          GoRoute(
            name: "splash",
            path: "/splash",
            builder: (context, state) => const SplashPage(),
          ),
          GoRoute(
            name: "signUp",
            path: "/signUp",
            builder: (context, state) => const SignUpPage(),
          ),
          GoRoute(
            name: "passwordReset",
            path: "/passwordReset",
            builder: (context, state) => const ResetPasswordPage(),
          ),
        ],
      );


static GoRouter mainRouter = GoRouter(
    initialLocation: "/main",
    routes: [
      ShellRoute(
        navigatorKey: mainNavigatorKey,
        builder: (context, state, child) {
          return Cookies(
            child: HomeCorePage(
              child: child,
            ),
          );
        },
        routes: [
          GoRoute(
            name: "main",
            path: "/main",
            builder: (context, state) => const HomePage(),
            routes: [
              GoRoute(
                name: "postDetails",
                path: "postDetails",
                builder: (context, state) =>
                    PostDetailsPage(postId: state.params['id'] ?? ""),
              ),
              GoRoute(
                name: "chat",
                path: "chat",
                builder: (context, state) => ChatPage(),
              ),
              //...........
            ],
          ),
        ],
      ),
      ShellRoute(
        navigatorKey: mainNavigatorKey,
        builder: (context, state, child) {
          return Cookies(
            child: SettingsCorePage(
              child: child,
            ),
          );
        },
        routes: [
          GoRoute(
            name: "settings",
            path: "/settings",
            builder: (context, state) => const HomePage(),
            routes: [
              GoRoute(
                name: "profileEdit",
                path: "profile",
                builder: (context, state) => const EditProfilePage(),
                routes: [
                  GoRoute(
                    name: "resetPassword",
                    path: "resetPassword",
                    builder: (context, state) => const ResetPasswordPage(),
                  ),
                ],
              ),
              GoRoute(
                name: "themeSetup",
                path: "theme",
                builder: (context, state) => const ResetPasswordPage(),
              ),
              //...........
            ],
          ),
        ],
      ),
    ],
  );

But I don't understand how to switch between the 2 GoRouters

In MaterialApp.router I can set only 1 GoRouter and the:

context.go(path)

can recognize only routes belong to the one sets on the MaterialApp.router.. What is the way to switch between routers instance?

Thanks!