I think we need to actually see and test the application before making any changes.
In particular, it would appear to have some serious shortcomings, especially with respect to recently introduced support for firewalld :
https://invent.kde.org/network/plasma-firewall/-/issues/16

lacking support for firewalld zones may be a deal-breaker. But, I'll reserve final judgement until there's something to test.

@apol, @ngraham: Is there any chance we could get the Plasma Firewall developer(s) to join us in the SIG meeting next Monday (as that's the KDE<->Fedora sync meeting)? We'd like to discuss using Plasma Firewall for our FirewallD frontend with them.

Yep, he'll be joining next week. I can too.

Putting this on next week's agenda then.

Looks like firewalld interfaces all require privilege. Not a problem for firewall-config since it essentially runs as root.
for org.fedoraproject.FirewallD1 dbus, we can write some policykit rules for access. In particular, a a first step would be to allow local users read access, and admin users write access.
The first question, was how to query firewalld vesion, command line variant:
qdbus-qt5 --system org.fedoraproject.FirewallD1 /org/fedoraproject/FirewallD1 org.fedoraproject.FirewallD1.version

@rdieter Did you contact Tomaz and work out the remaining effort here?

No, I thought my only task was to work on the policykit conf, sorry

I reached out to Tomaz but did not get a reply yet. Pinged him.

We're basically out of time for making this change for Fedora 34, so we're going to defer this for Fedora 35. Regardless, it'll be in the repositories for folks to try and use.

FYI new source is https://invent.kde.org/plasma/plasma-firewall.

Btw what were the summarized steps left?
PolicyKit
Anything else?
Firewall Zones: https://invent.kde.org/plasma/plasma-firewall/-/issues/16 << Tracking Issue

PR to add polkit rule to firewalld allowing use by "admin" users
https://src.fedoraproject.org/rpms/firewalld/pull-request/7

firewalld zones tracking issue moved to https://bugs.kde.org/show_bug.cgi?id=434954

cc: @ngraham who filed #72 (which is a dupe of this ticket).

lol so I did

We're waiting for zone support...

Is there any updates on this worth mentioning?

Is there any updates on this worth mentioning?

Negative, the person that was working on implementing zone support upstream doesn't appear to be working on this anymore. It would need developer resources to get the upstream support added.