pseudo code to filter mutations to not execute if they're duplicate requests. . .see: https://github.com/wp-graphql/wp-graphql/issues/602#issuecomment-460791863

wp-graphql.php

add_action( 'graphql_before_resolve_field', function( $source, $args, $context, \GraphQL\Type\Definition\ResolveInfo $info, $field_resolver, $type_name, $field_key, $field ) {

	if ( 'RootMutation' === $info->parentType->name ) {
		$type  = \WPGraphQL\TypeRegistry::get_type( $type_name );
		if ( isset( $type ) && ! empty( $field = $type->getField( $field_key ) ) ) {

			if ( isset( $field->config['isPublic'] ) && true === $field->config['isPublic'] ) {
				if ( true === true ) {
					throw new Exception( __( 'This mutation has been executed too many times in the allowed timeframe', 'wp-graphql' ) );
				}
			}
		}
	}
	return;

}, 10, 8 );