pmbootstrap flasher boot. But you’ll always need a PC to boot it and can’t use a pre-built image.
Afaik they were supposed to do a movie still but that sadly never happened.
I agree with you, just leaving that galaxy behind was a very disappointing ending.
I’m not sure I understand what you’re saying. Plasma’s Discover allows installing and updating exactly the same apps as GNOME’s Software Center do. There is no “segmentation” there?
And that “standard packaging format that works on all Mobile Linux platforms” is basically Flatpak, and we support it. Not sure why Ubuntu Touch doesn’t, but that’s their problem, even SailfishOS supports it nowadays.