Optimize alloptions: remove option if size more than 1MB.

add_action( 'pre_cache_alloptions', function( $alloptions ) {
	foreach ( $alloptions as $key => $value ) {
		$size = strlen( maybe_serialize( $value ) );
		if ( $size > 1000000 ) {
			unset( $alloptions[$key] );
		}
	}
	return $alloptions;
} );