The buffer is only available on the wired version. The battery doorbells don’t have that functionality even if you wire it. The AC from the doorbell transformer is only meant to trickle charge the batteries and doesn’t grant any additional functionality to the doorbell.
The Homebase does grant some protection if the device is stolen or damaged, but its not foolproof. See this thread.
https://communitysecurity.eufylife.com/t/major-flaw-delete-homebase-data-via-camera/903359
I haven’t tested the doorbell, so not sure if the flaw is the same, but since all other devices have the issue, it’s best to assume it does.