@kristoff @purplemonkeymad All of these are in-place same-disk snapshots. The ChomeOS system is simpler and so can be automated but you only get 1 level of undo.
I don’t know any mainstream OS that does dual-failover. Deepin Linux has 2 root partitions but I don’t know how it uses them.
I think Valve SteamOS does something like this. It’s not just for games: it has KDE built in. There are guides to getting it running on your own hardware. You will want AMD graphics, though.
@kristoff Not really… On ChromeOS, there are no apps.