Cannot set "-log-bytime" log rotation option for s service plan via CLI. For example, it still remains set to "weekly" in Plesk > Service Plans > Example Plan > Logs & Statistics after running the following command:
C:\> plesk bin service_plan.exe -u "Default Domain" -log-bytime daily
This is Plesk bug with ID PPPM-7574 which will be fixed in future updates.
As a workaround, specify "Daily", "Monthly", "Weekly" with upper-case. For example:
C:\> plesk bin service_plan.exe -u "Default Domain" -log-bytime Daily