Lookup Taxonomy term ID using term name from CSV

I am porting some content to D8 from a SharePoint site via CSVs. However, the taxonomies and users were migrated manually, which means I cannot us the Migrate plugin to lookup the ids from the term name. For short taxonomies, I have successfully used the map plugin, but this is a serious challenge for taxonomies with lots of terms. So far my migration is all config (yml) with no callbacks or other php.

Is there a way to handle this in the yml?
If not could it be easily handled with the callback plugin?

Any help will be appreciated.

Drupal version: 


Source: https://www.drupal.org/taxonomy/term/37/feed