disable-plugins.php

<?php

/**
 * Filter the list of active plugins for custom endpoint requests.
 *
 * @param array $active_plugins The list of active plugins.
 *
 * @return array The filtered list of active plugins.
 */
function filter_active_plugins( $active_plugins ) {
	if ( ! is_custom_endpoint_request() || ! is_array( $active_plugins ) ) {
		return $active_plugins;
	}

	$allowed_plugin_files = array( 'setary.php', 'woocommerce.php' );
	$filtered_plugins     = array();

	foreach ( $active_plugins as $plugin ) {
		foreach ( $allowed_plugin_files as $allowed_plugin_file ) {
			if ( strpos( $plugin, $allowed_plugin_file ) !== false ) {
				$filtered_plugins[] = $plugin;
				break;
			}
		}
	}

	return $filtered_plugins;
}

add_filter( 'option_active_plugins', 'filter_active_plugins' );

Thanks for sharing! One last question I have, how do you decide when it's a custom endpoint request? Do you simply check the endpoint that's being called?

@Dan0sz I just check if the path contains wc/setary, but you could also pass an additional get parameter ?setary=1

Man, this is interesting. And so simple! Thanks a lot, man!