Hi, getting lots of (in WP Debug logs):
PHP Notice: Trying to access array offset on value of type bool in /var/www/html/wp-content/plugins/multisite-enhancements/inc/autoload/class-add-admin-favicon.php on line 21

WP: 5.4.2
PHP: 7.4.8

Love the plugin, been using it for years. If I get some time I'll try to put a PR together on this.