Posted this in Reddit some days ago, I would like to share it also there.
Following my first attempt to improve the LuCI interface so that Firewall rules would be displayed in separate tabs based on their originating zone: OpenWRT-Viewer, this is my second attempt, implemented directly in LuCI without using an external server.
Just check the README file
Small tip - list devices in zone.
What do you mean?
Just show zone members list somewhere
Oh Ok, this could be a good idea, maybe I can add a column the "Enabled" one.
Btw, you can find the source zone under Match conditions column (From)
I just thought user can reach context info without losing current tab 
Well, assuming, and simplifying, that you need to check why a specific device in a particular zone (e.g., WIFI) is not connecting to the internet or cannot reach a specific service, navigating to the tab where all the rules are listed can be frustrating, especially if you have a lot of them. With this division, you can go directly to the WIFI tab and check only the rules specific to this zone. After all, this is the view that all firewalls implement (e.g., pfSense, OPNsense, etc.).
The tab with all the rules is always available, so you can review the entire flow. But if you only need to check a device in a specific area, in my opinion, it is much clearer to divide the rules by zone. The order in which the rules are executed will be relevant only to that zone.
In fact, if I need to understand what one or more devices in a particular area are doing, what is the point of knowing the execution order of rules for all zones?
Sure, you always have access to the firewall log, but this way, at a glance, you'll see the rules for a specific device/s.