As I wrote earlier, I have been using the SpiderOak One Backup service for a while now. It costs more than the usage of Duplicity with Backblaze B2, but it promises to work better. Also it creates backups continiously, so I don't have to wait for the full hour to have a backup. Using inotify it will automatically put files into the queue just as I save them. I really like this. My laptop could burst in flames and I would only lose a few minutes of work.
But the performance of the system is bad, again and again. I recall that I tried the service a few years ago and had just exactly the same issues with it. Often it would not utilize my upload bandwith (10 Mbit/s) fully but rather utilize one full CPU core, which seems excessive. I would restart the application and then it would stop this. Often this is triggered by using the GUI. I have the feeling that the GUI cannot really cope with ten thousand of files being listed, so it just freezes up as it tries to display it all.
Lately even restarting did not help. So I wrote to the support on 2020-05-23 about this issue. I got a reply telling me to move the
~/.config/SpiderOakONE directory somewhere else and sign back into the program. Then it would do the syndication again and it should work fine. At the time it seemed to work fine again after a few simple restarts, so I did not follow through on this at that time.