H4 To H1B Change Of Status - Payroll Start Date

I got my H4 to H1B Change Of Status from 10/01/2023.

1.) At what point should my employer initiate payroll? What implications arise if it’s not started within the initial 60 days for my status?
2.) If payroll commences on the 61st or 62nd day, how might it impact future matters? Is it permissible for payroll to start after 3 months? Seeking guidance on this.

If you are already present in the US amd your status change to H1B, you are considered employed on H1B as of the start date on the I-797. So your employer is expected to start running payroll based on their weekly/bi-weekly process.
If they dont pay you, they are in violation of H1B employment rules.