Use ACF fields for meta descriptions via excerpt extraction in The SEO Framework plugin, supporting both admin and front-end contexts.

tsf-acf-html-excerpt-description.php

<?php
// Do not include the PHP opening tag if PHP is already open.

// Per email Wojciech.

add_filter(  'the_seo_framework_description_excerpt', 'my_tsf_acf_custom_excerpt', 10, 3 );
/**
 * Use ACF HTML fields as meta description for specific CPTs.
 *
 * @param string     $excerpt The auto‐generated excerpt.
 * @param array|null $args    Query args ( [ 'id','tax','pta','uid'] ) or null.
 * @param string     $type    Description type: 'search','opengraph','twitter'.
 * @return string
 */
function tsf_acf_meta_desc( $excerpt, $args, $type ) {

	// Bail if ACF isn’t active.
	if ( ! function_exists( 'get_field' ) )
		return $excerpt;

	// Determine post ID.
	if ( isset( $args['id'] ) ) {
		$post_id = (int) $args['id'];
	} else {
		// Only proceed on single views.
		if ( 'single' !== \The_SEO_Framework\get_query_type_from_args( $args ) ) 
			return $excerpt;

		$post_id = tsf()->query()->get_the_real_id();
	}

	// Map CPT → ACF field.
	$map = [
		'member'   => 'tm_desc',
		'practice' => 'i_fulldesc',
	];

	$cpt = get_post_type( $post_id );

	if ( ! isset( $map[ $cpt ] ) )
		return $excerpt;

	$html = get_field( $map[ $cpt ], $post_id );
	if ( ! $html )
		return $excerpt;

	// Extract HTML content considering its tags.
	$text = tsf()->format()->html()->extract_content( $html );

	return $text ?: $excerpt;
}