How to translate custom content block title? How do I properly translate custom content block titles?

Problem:
I've got a custom content block with just one CKeditor text field. I want to show the custom block title and the text field. When I place that block, the PLACED block title is copied from (but not referencing) the custom content block.

When a content translator later translates that custom content block, the PLACED block title is wrong/untranslated. Is there a way to reference the correctly translated, custom content block title in block placement? E.g. using tokens?

NOT allowed solution:
Giving translators access to block placement to translate the block placement is an absolute no-go. They are only allowed to use custom block library.

Unwanted workaround:
I know I could create an additional fake-title field and disable "Show title" in block placement. But I really hope I can avoid this, or I would have to modify all my existing block templates.
To use the title from the custom content block entity (not the title from the block placement config):

function mymodule_preprocess_block (&amp;$variables) {
  if ($variables ['elements'] ['#base_plugin_id'] == 'block_content') {
    $variables ['label'] = $variables ['content'] ['#block_content'] -&gt;label ();
  }
}


This also respects translations and does not require access to block placement for translators.