This is a minor nitpick, but I don't think postmarketOS is GNU/Linux. I am not sure what the correct term would be to refer to the group of operating systems i

This is a minor nitpick, but I don't think postmarketOS is GNU/Linux. I am not sure what the correct term would be to refer to the group of operating systems including those you mentioned but excluding Android, since all of them include Linux, but it does seem like there's something different about Android that puts it in a different category compared to other Linux-based operating systems.