Overriding Meta save for Taxonomy Terms

[letusbuild]

Hello,

I have both a question, but also an idea for snippet if others feel it is of any value.

GOAL: save as terms instead of meta in a frontend form where a field is using the ajax_term_search custom field type and is querrying terms from 4 different taxonomies – each of which has several hundred terms. (thus reason for ajax support here.)

SITUATION:

• 4 taxonomies: each has 300 - 1,000 terms.

• a single field is used to query the terms from 4 taxonomies at once, but the goal is to override the saving so that the selected terms are not saved as custom meta, and instead are saved as terms against the object under their same individual taxonomies.

Issue
How would the existing "meta override" snippet be altered when/if querrying multiple taxonomies in a single field when using either ajax_term_search custom field type, or other custom select that allows a user to select multiple terms and save against post?