But I guess what I'm getting at is: is it following the "principle of least astonishment" to to no longer make backups simply because the server is off?
If somebody set up an Archive every 24 hours at 05:00 and the server crashed at 01:50, would the admin (who didn't wake up in time to bring the server up at 05:00) want no archive to be made, and for the next available archive to be the following day at 05:00?
For backups, it seems less drastic, since people might be making hourlies, and backups would be available from 01:00 to when the admin woke up, e.g., 07:30, but what I guess I'm saying is: what would an admin expect the behavior to be.
Brainstorming a bit, I think maybe a perfectly good indicator would be in the webui when the server is DOWN, perhaps the dashboard/server-at-a-glance might have an indicator "The server is down, but you have cronjobs running!".
That or maybe creating a separate function that only backs up/archives while the server is running (so, two new options in the cronjob dropdown). These might provide the function you're looking for without behaving unexpectedly.
Keep in mind, as the designer, I tend to choose UI options that err on the side of caution. I'd rather hear "why is there not-useful backups being made while the server is down" over hearing "why don't I have the backups my schedule is set to?" since progress-loss is one of the angrier complaints I personally have to cope with.
I tried at one point setting the functionality of auto-pruning restore points after X backups, but it started behaving erratically, so I couldn't pull it into the master. Perhaps I'll look into that again, so that there's never a 10-15 second delay, since that is....way to much.