What is the normal span of time for the completion of DoorDash background checks, and are there any such factors or variables that may influence the time taken by them? Could you, please, give insights on the question: how long does doordash background checks take? In particular, are there any certain elements or components within the background check process which would cause the extension of processing time, and what steps has DoorDash taken to streamline and speed up the background check process for potential Dashers? In case there is a delay, what are the communication channels and support mechanisms put in place by DoorDash to keep applicants informed of the status of their background checks, and what resources are available for any concerns or queries regarding the duration of the background check? Lastly, how does DoorDash balance the need for a thorough and comprehensive background check with the importance of providing a timely and efficient onboarding experience for individuals wanting to join the platform as Dashers?