Is there an organized changelog / release history of controller firmware? (both GA and Insider)

Insiders have a changelog to check for firmware changes, while official updates are included in the blog. Missing a direct integration in the dashboard, it's true, it would not be a bad idea.

I'm going to assume you did the controller firmware update when the latest release pushed to your console? If you didn't give it a shot and see if it helps. There is also an update in the April preview to address two issues with the previous controller
firmware:

*NEW CONTROLLER FIRMWARE UPDATE*

Update to help address controller disconnect issues.

Update to help address headset adapter audio quality.

That is from the release notes in the forums and since applying the update to my controller, I haven't had any issues with this since. So if you have the latest firmware applied hang in there, and when the April preview goes GA, try updating it and see
if it resolves the issue at that point .

State of Decay title update 2 will release next week - read the full changelog in link.

Now in certification testing, says Undead Labs



www.oxm.co.uk/.../state-of-decay-title-update-2-will-release-next-week-read-the-full-changelog-here

You can try updating the firmware to the latest version, but from what I saw in the changelog there's probably nothing that will make UPnP function better.

Thats not a changelog, not by a far, and neither it is official. When google released Android 5.0, they provided a changelog, it had all the 128,680 changes listed. Sure bit over the top, but this generic "Mandatory update that prepared for subsequent growth
of the service" is just SAD.