I'm testing your component but I have a problem to translate the string of custom fields.
I have this situation:
1) I have created checkboxes custom field and in Text I set a string translation:
2) I have created the language override:
3) When I edit an article the translation override is visible:
4) and also in frontend the translation string is visible:
but in the module filter is not visibile:
What am I doing wrong?