Immutable/offline backups. If you backup to local physical media (HDD/tape), physically disconnect/eject it and store it somewhere safe. If you back up to cloud storage (S3, etc), many of them have immutability options. If configured properly nobody (not even you) can delete or modify the backups (within the specified time period).
I think it’s probably more than confirmation bias in this case. Twins generally have a lot of shared experiences and environment. It’s not surprising that they would more dialed in to how their sibling thinks/responds.
But quantum entanglement has nothing to do with it.
Is it giving an error code, or just glitching out? I just repaired my Samsung control board. It would glitch out (display goes nuts, relays clicking). I found that there was cracked solder joints on the main board relays. I resoldered them and it’s totally fixed now. I think the bad connection causes the relays to pulse which creates back-emf that glitches the display. Getting the board out of the potting compound is annoying and messy, but otherwise it was an easy fix.
There’s no need to touch the springs at all when replacing the opener. But this is still an excellent PSA. Garage door springs will seriously mess you up before you even know what happened. I’ve replaced them before, but you definitely need the right tools and procedures to do it safely. I would definitely advise against it unless you have experience.
I’d probably go with some sort of split cover plate/flange (or a regular non-split one if you can disconnect it to feed it through). If you have access to a 3D printer, you can make one that way pretty easily. If not, you can probably find one at the hardware store or online that would work.