FYI, when you have an issue with a custom handler you should post it to the handler’s topic so that the developer receives a notification…
The built-in handler is missing tons of features so I recommend continuing to use the custom handlers you linked to.
Aeotec recommends using the custom handler and there’s documentation on their website that covers how to use it.
They recently updated it, but unfortunately it still has a comment about not being able to configure it with the classic mobile app which isn’t true.
When you open the parent and change any of the settings it should create a child device for each of the buttons that are paired to it, but those child devices most likely won’t get assigned a room so you’ll have to look through your whole device list in the mobile app.
When you find the child device for the doorbell go into its settings and that’s where you’ll be able to specify the sound, volume, repeat, length, and strobe effect that gets played when the doorbell button is pushed.
When the physical button is pushed the device generates button pushed and switch on events so you should be able to use either of those to trigger automations. In theory you can use the device’s switch on command to play the button’s sound, but if you want to play sounds on the fly with Automations you’re better off using the parent device.
The dimmer field for the parent device in Automations will play the corresponding sound number using its chime related settings, but you’ll have to set the “Switch On Action” to “Do Nothing” because when you use the dimmer action in Automations ST executes the devices on command before the setLevel command.