I flashed the new Fedora KDE Plasma Mobile Spin 41 to a PinePhone and it boots!
I already had Tow-Boot, so I just had to start the device while holding down volume-up, and then connect the USB cable and flash with Balena Etcher. WIth verification included, it took more than half an hour, but then again the image was large (11GB uncompressed).
Can't get past the Initial Setup though. First, not everything fits into the screen. Second, I see the Wi-Fi enabled but don't see a way to choose the network (possibly because of the first problem).
Nevertheless, I hope one day soon I will have this running.