The Multi-Currency plugin hooks into client forms and detail pages: Adds "Currency" field to client edit form via app_portal_client_form_after_tax_id hook Saves currency preference to _client_currency post meta Returns currency data when filtering client objects Auto-suggests currency based on client's country selection The Invoice Enhancements plugin displays templates on client detail page: Hooks into apapi_client_detail_sections to render template section Fetches all templates associated with the client ID Provides AJAX endpoints for template management Links templates to client for quick invoice creation