How to improve integration of Frient Electricity Meter?

About three months ago, I successfully set up the Frient Electricity Meter (EMIZB-151). It’s connected to Home Assistant via ZHA and the SkyConnect dongle. The connection has been rock-solid, with updates visible every few seconds.

However, the default integration only shows some of the available values. For example, under “Power,” only the reading for Phase A is displayed, while the values for Phases B & C are missing.

It seems like this might be an issue with the Zigbee integration. The missing values are accessible when using “Manage Zigbee Device,” but they don’t appear in the standard UI.

I’m happy to help improve this, but I have no prior experience with the Home Assistant codebase. Could someone guide me on where to start and how this improvement could be implemented?