Language Middleware: the default language for path based routing?

[shiny]

I want to use Language Middleware #3785 to achieve the following:
Accessing /home, the default language is English
Accessing /ja/home, the language switches to Japanese.

According to the documentation /ja/home works
https://hono.dev/docs/middleware/builtin/language#path-based-routing

app.get('/:lang/home', (c) => {
  const lang = c.get('language') // 'en', 'ar', etc.
  return c.json({ message: getLocalizedContent(lang) })
})

but how to make the :lang optional and fallback to the fallbackLanguage?
Do I have to write it twice?
app.get('/home', ...) and app.get('/:lang/home', ...)
since app.get('/:lang?/home') didn't works.

[shiny]

For now, I write it like this, though I wonder if there might be a better method.

localizedApp.get('/home', (c) => {
  const lang = c.get('language') // 'en', 'ar', etc.
  return c.json({ message: getLocalizedContent(lang) })
})
app.route('/:lang{ar,ja,en}', localizedApp)
app.route('/', localizedApp)