Hopefully this is useful to someone on here:
Withdrawal of CEC PR Application 2024
I submitted my application CEC in September 12, completed biometric and medical in October 30 but I latter realised I made mistakes in my documentation that would affect the validity of my application and not meet the IRCC standard.
So I summited a request for withdrawal through webform: November 24th
Got a response: November 28th
Withdrawal confirmation letter: December 2nd
I do not regret withdrawing my application so I can submit a better application in future.
Please be proactive with your application so you don't get into serious issues.
HOW TO WITHDRAW YOUR APPLICATION
https://secure.cic.gc.ca/ClientContact/en/Application/Form/74
please make sure your create a handwritten withdrawal letter and signed with your receipt of payment uploaded to your webform.