I’m not trying to be overly dismissive of your concerns, but aren’t most instances run on some dude’s spare computer for shits and giggles? I wouldn’t expect continuity or risk management at all. But also, nothing is lost but a little convenience if one disappears.
Two admins recently gave up and shut down their servers, which is another thing to consider. Some kind of export / archive tool might be useful. Not sure if importing would be a thing due to resources it would take, but who knows.
Actually this made me think. Wouldn't it be cool to be able to download the data of the instance? Like an automated system that has for example the last backup of the instance and there you could download it. That could be used to preserve user data if the host gets hit by a bus.