I current have a couple devices which are connected using ZHA, but one feature I feel is greatly needed is the ability to configure the device without needing to resort to setting the relevant cluster manually. Personally, I would have loved this feature recently when I was setting up a Aqara Blind Roller as I was wanting to change its speed but of course had to find the relevant cluster to change it
Exposing common configurations (as well as common manufacture specific configurations) would greatly improve the ZHA experience, particularly since I could then use these configurations in automations (based on my own experience setting a slower speed at night and when I wake up)