Actually, when you add custom fields to a taxonomy they are added to the terms in the taxonomy. This is why whey you get the values from the fields the $post_id that you use is {TAXONOMY}_{TERM_ID}. The custom fields are associated with the term, not the taxonomy.
Honestly, the only thing I can think of that will change will be that I’ll be able to search terms based on term_meta values rather than needing to get the terms first and then check the custom field values on them.
