Does my monthly Switchboard cost also cover usage charges? (voice minutes, SMS messages, etc)

Your monthly Switchboard cost does not include the cost related to your monthly phone number (pay-as-you-go) usage. You are charged for this directly by Twilio - this cost breakdown is available on the Twilio Pricing page.

Switchboard uses Twilio’s Connect mechanism to manage your phone numbers which results in you having full control over your account. You can find more information about Twilio Connect and how it works here.