You should definitely not use the following:
_Enterprise Server_ClientRegister_MaxChildCount=0
This will prevent any client from registering the root as it’s relay. This is a bad thing because some endpoints will connect to the root because they don’t have another option. This is their fall back. If they cannot connect to the root then they become effectively unmanaged.
You want to do what you can to get clients to use relays other than the root, BUT you also want clients to be able to use the root as their relay when they don’t have another option.