A couple of security questions ...

[Crispy]

BTW: Can anyone recommend good backup software (for windows)? Preferably without proprietary storage format. One option which I have used before is a script using Robocopy, but I suppose dedicated software will be easier to maintain.

FileHistory. It's free and is included in Win10/11.

Just search for it in Control Panel, enable, select the drive you want to use, and let it do its thing. Runs in the background, does automatic incremental backup on subsequent recognition of the drive, does not use any form of proprietary format.

In Windows 11 it's hidden (of course), but can still be used by manually launching Control Panel then searching in Control Panel's upper-right search box "File History".

Simple and effective.