ezplatform url( ez_route not mapping to route of domain

I have a simple site, the base language is English with a translation of German.

Here is the site-access setup from the ezplatform.yml

# Siteaccess configuration, with one siteaccess per default
siteaccess:
    default_siteaccess: en
    list:
        - en
        - de
    groups:
        site_group:
            - en
            - de
    match:
        URIElement: 1

# System settings, grouped by siteaccess and/or siteaccess group
system:
    site_group:
        api_keys: { google_maps: "xxx" }
        cache_pool_name: '%cache_pool%'
        var_dir: var/site
        translation_siteaccesses: [de, en]
    de:
        languages: [ger-DE, eng-GB]
    en:
        languages: [eng-GB]
    default:
        content:

Works great, accessing localhost:8000 displays english content, and localhost:8000/de displays german content.

I then built a simple language switcher:

<ul>
    <li>

        <a href="{{ url( ez_route( null, {"language": "ger-DE"} ) ) }}" {% if ezpublish.siteaccess.name == 'de' %}class="inactive"{% endif %}>
            Deutsche
        </a>
    </li>
    <li>
        <a href="{{ url( ez_route( null, {"language": "eng-GB"} ) ) }}" {% if ezpublish.siteaccess.name == 'en' %}class="inactive"{% endif %}>
            English
        </a>
    </li>
</ul>

But now i see there is a problem with duplicate content for SEO. When on the german site-access, the language switcher prints a link to the en site access for the eng-GB language as localhost:8000/en where it should be localhost:8000.

How can i tell ez to either redirect all /en content to /? I think there must be a better solution, but i don't see how in the docs :/

When i change how the matchers work to this:

siteaccess:
    default_siteaccess: en
    list:
        - en
        - de
    groups:
        site_group:
            - en
            - de
    match:
        Map\URI:
            /: en
            de: de

For the english translation i get a // in the url for english.

We're using this matcher config and it works okay:

ezpublish:
    siteaccess:
        match:
            Compound\LogicalAnd:
                cro:
                    matchers:
                        Map\URI: { cro: true }
                        Map\Host: { '%site_domain%': true }
                    match: cro
            Map\Host:
                '%site_domain%': eng

Note that I'm using %site_domain% parameter which I defined myself in app/config/parameters.yml. You can do it too, or you can use a hardcoded value.

The downside is, you need to add all new siteaccesses to the list in Compound\LogicalAnd matcher, but if you have a simple site with couple of siteaccesses, it should be fine I guess.