How to create a non-routeable container route for go_router(_builder) ShellRoute?

Question

I'm building an app with Flutter.

Consider the following routes in the app:

/section-a/a
/section-a/b
/section-a/c

/section-b/a
/section-b/b
/section-b/c

Each section could also have more children with children having children. Typical nested routing.

I'm using go_router (10.0.0) and go_router_builder (2.2.1) to build the basic infrastructure like this:

const $sectionARoutes = [
  TypedGoRoute<...>(path: '/section-a/a'),
  TypedGoRoute<...>(path: '/section-a/b'),
  TypedGoRoute<...>(path: '/section-a/c'),
];

As you can see, I have to duplicate the string section-a in each route.

Now, my idea was to make a container route with children:

const $sectionARoutes = TypedGoRoute(
  path: '/section-a',
  routes: [
    TypedGoRoute<...>(path: 'a'),
    TypedGoRoute<...>(path: 'b'),
    TypedGoRoute<...>(path: 'c'),
  ]
)

Now, I don't need to duplicate that string and visually it looks the same.

However, when I'm, e.g. at location /section-a/a, I can do a swipe gesture beginning on the left side and swipe to the right ("navigate back" swipe) and then my location is /section-a showing a white page (SizedBox.shrink()).

That's because the TypedGoRoute(path: '/section-a') is also a valid viewable target.

However, that's not what I want. I basically search a way to define a parent that I can not route to. Is that possible?

I tried specifying a redirct for the parent route, however this only works when routing to that page directly, but is not taken into account when "navigating back" (could also be a bug in the go_router).