no issue - Previous library was relyting on try/catch block to check if the expression is valid. Flow control through error catching is not considered a good practice and can effect performance (https://riptutorial.com/javascript/example/5297/avoid-try-catch-in-performance-critical-functions)
no issue - CRON format is the most common one used for job scheduling and is well known to most developers - This will become one of supported formats for job scheduling