I saw this announced on the KiCad forum when grabbing the forum link for another thread. It looks very helpful for panelising (including with / without rails) and seems well documented. The only hiccup I can see for some of us is that it didn’t work with Python 2 in Windows and was waiting for KiCad 6 to “fix” that with Python 3. So I don’t know if it has been tested on Windows / KiCad 6 yet. I have not dug into the CI / automation tools yet but they may be a good alternative to eg kibot.
Again, feel free to comment or correct me below but here’s the KiCad forum thread too!