Welcome to the forum @Jochem
It probably depends on what parts you read. Some seems fine. Comparison to CrashPlan seems off…
I’m not going to run a word count to see if “generally incorrect” fits, but I’ll do a deeper dive on it below.
The first bullet covers files that still exist, so doesn’t apply. The second bullet covers deleted file losses from their backup aging past the longest time frame as was discussed in the posts just above that one
It doesn’t, however, cover the point that deleting a backup makes things as if the backup didn’t happen. Some people might think that’s obvious, however others would miss it, so some support volunteers may specially point out the risk you cite. It would be nice if the manual could point it out. Care to try to write?
GUI smart and custom backup retention aren’t covered #83 (seeking help on explaining a messy topic)
Part below is your worry, right?
People who actually think this through thoroughly may realize (or may be told in the forum) that a file which exists (between creation and deletion) for a time less than current minimum interval (which can increase with time) may disappear completely. This may matter to some people, but there’s a limited amount that can be said. Would it be better to have an “advanced” section for those wanting it?
CrashPlan has special features for deleted files. Are you familiar with those, or other backup programs?
Aside from improving documentation (help wanted, as with everything), what change might you advise?
Migrating from Crashplan - Retention & other general questions covers the difference and your warning.
looks to me to give a very concise summary, and “will remain one backup” is a clue. Certainly, it could expand a bit (if someone volunteers), but I wouldn’t want it to be a book. That’s what the manual is for.
One also has to understand what you describe, which is that a backup is a point in time of the system.
Bringing up CrashPlan again, it blurs the line between system and files. A volunteer plans work below:
Implementing the feature to restore any version of a single file (features can happen given volunteers)
Great advice but I wonder if publicity of this whole area can improve? Documentation can possibly find volunteers, but not often. Actual code (not just message changes) is even more seriously understaffed.
Duplicati relies on volunteers from the community, and that’s what limits the progress that can be made.