Reply To: POST meta fields to tags

Just an update for this for anyone following, I found a partial solution that fixes posting custom taxonomies with meta_box parameter via rest api.

In file mb-rest-api/class-mb-rest-api.php line 155 is

$field = rwmb_get_registry( 'field' )->get( $field_id, $object->taxonomy);

It should in fact be:

$field = rwmb_get_registry( 'field' )->get( $field_id, $object->taxonomy, 'term' );

I will continue investigating why builtin taxonomies do not get their meta_box fields passed in and saved at all.