Our current APIs allow a single listener instance to listen on multiple notifications, which is appropriate for a number of use cases we currently cover.

Unfortunately we do not support atomic registrations for multiple listeners to particular notifications. This results in mdsal-binding-dom-adapter having to perform an additional dispatch to support FooListener contract, as once it receives a callback on its DOMNotificationListener, it needs to go back and look up which notification method needs to be invoked.

We could do much better if we offered a way for each subscribed notification type to be dispatched to a corresponding listener – eliminating the need for a secondary lookup.

This would also offer additional flexibility for binding-dom-adapter, as it could efficiently support its users' subscription to multiple notification types in a type-safe manner.