Hello,
The ADC-W115C Smart Doorbell Chime is compatible and supports the features you are looking for. This device plugs into the wall via AC adapter, but communicates over wifi.
It allows for adjustable volume and custom tones, which can be controlled remotely via the Alarm.com platform. This chime is specifically designed to work seamlessly with your ADC-VDB750 doorbells, ensuring that each door can have its own distinct sound.
You can find more details about the Alarm.com Smart Chime in the forum post here and the product manual is linked here.