If all settings are done with annotations on the post type class, then how do I translate a field name (or the name of the post type itself) ?

How about doing an automatic __( $field_name, $post_type_name ) when the post type is actually registered in wp? That should not give any problems for people who don’t translate anything since they will get the expected $field_name string from the annotation.

https://www.ads-software.com/extend/plugins/posttypebuilder/