Onboarding process for subaccounts for GHL agencies, Twilio & LC Phone, Twilio account setup etc.

It is very difficult to understand what the onboarding process for adding your subaccount users and the Twilio portion of setup. It's easy to understand the ghl integration process. Is there any documentation for the actual onboarding portion of twilio/subaccounts. Adding a subaccount automatically pulls in our main twilio and we don't understand how to automate creating a twilio subaccount. Usage is charged to us if done this way. Also users can access our twilio info when we import every subaccount from ghl through the marketplace. Just a little guidance on the two main ways someone could onboard with ghl (not the snapshots) but twilio