Menu block displays wrong language when only using content translation

Background:

The website we are building will support two different languages, and all the content is being translated so there are versions for both.

However, we have not turned on interface translation, since we want the drupal interface to remain in English, as that is what the site editors are most comfortable using.

The Problem:

When switching to the alternate language of a page, the menu blocks items are remaining in English, and don't change unless you clear the render cache.

The Cause:

Despite the menu items being content that is translated using content translation, the rendered menu blocks are being stored in the cache using the interface language instead of the content language, such as:

cid: entity_view:block:site_name_main_menu:[languages:language_interface]=en:[route.menu_active_trails:main]=menu_trail.main|menu_link_content:8c16c3a4-f165-4ea4-b2b4-07a1cee8e592|:[theme]=site_name:[user.perm-AjQCijrXHvxvgiuYXJCT4T4GgXa1tNWosi6GEgeN5Y

The Solution?

Could we switch menu blocks over to using the content language instead of the interface language? Or should we store both, so a rendered copy of the block is stored for each interface/content language combination?