I don’t know if that plugin will do what you want or not, first I’ve heard of it.
Ad far as doing this with code it would work in a similar way. The biggest difference would be that anywhere that you’re getting or setting a value, instead of $post_id
you would use 'term_'.$post_id
for the post you want to get or set the value from. The value you’re setting would be the same $post_id
as this would be the term ID for a taxonomy field.