Deploying permission sets from a sandbox to production following best practices involves using change sets. Change sets allow administrators to push configuration changes, such as permission sets, from a sandbox environment to production in a controlled and secure manner. This method ensures that all configurations have been tested in a non-production environment before being implemented in production, reducing the risk of errors and maintaining system integrity.

Adding more support phone lines is a solution that can address the problem of the support team being unable to provide same-day customer assistance due to high demand. Adding more support phone lines can increase the capacity and availability of the support team to handle incoming calls from customers. This can reduce the wait time and improve customer satisfaction. Verified Reference: : https://help.salesforce.com/s/articleView?id=sf.service_phone_overview.htm&type=5 : https://help.salesforce.com/s/articleView?id=sf.service_phone_setup.htm&type=5