Whats the most effective way for me to listen to add/update/delete events on all children under a couple of DatabaseReferences in my RTDB?

Im asking because Ive noticed that my apps memory footprint grows substantially when signed into firebase and using childEventListeners. By default the memory usage sits at about 40 mb, with the listeners active, 170 mb.

My data is categorized as such that 6 branches hold data, each under /path/uid/... each path has 300-3000 children that Im interested in syncing changes down to the device in a timely manner. I do this by adding a childEventListener to each, which covers all the childrens add/update/delete events.

Is there another more effective approach to this; or is this expected? I do notice that the overall performance of my app degrades while the sync is active.