Have you tested restores? The problem I had with duplicati was that eventually restoring from a backup would take exponentially longer, to the point of never finishing. Maybe it would have eventually, but I can't wait multiple days to restore one file. There's a possibility it was an error or problem on my end, and this was a couple of years ago, so ymmv.

Yes, we did test that and it worked reasonable fast (backup to external USB SSD)

I'm a new user of Duplicati and so far so good, but what you describe sounds like their biggest issue with the original storage mechanism (full+huge chain of incremental backups). The new mechanism would likely completely fix your concern. Here's a brief description of how it now works on their website: https://www.duplicati.com/articles/Storage-Engine/

The one full-backup restore I did on my wife’s system - after her MacBook Air decided to fry its storage (it was obsolete anyhow) - went perfectly. 23Gb of personal files (she’s not the data pack rat I am) came streaming back down inside of 20 hrs. And we were on a much slower connection at the time, certainly not the symmetrical gigabit that we have now.

> running without issue (AFAIK ^^)

If you don't know, then it's not working. At least that should be your stance on backups.