I have a Minio cluster setup and I am performing direct to object storage backups (no backup copies, no SOBR offloading).
My Minio bucket is setup without immutability or versioning. About as plain as it can get.

My backup job is setup with storage optimization set to 4 MB and retention policy set to 3 restore points - no GFS policy set. Basically default settings, with the restore points and storage optimization changed. I wanted to get a sense of storage usage over time and object sizes over time without complicating matters with immutability. After the initial backup it looks pretty standard - lots of 4 MB objects, few 1 MB objects and a smattering of under 1024 B objects. Pretty much what I would expect to see.
The curiosity came in after the retention policy started to prune out older restore points. The 4 MB and 1 MB objects remained relatively similar (the bumps in the graphs are when new backups are taken, before the old ones are aged out), but the under 1024 B objects started increasing significantly. As I understand it, that's all metadata, but what I'm confused about is why the significant growth of metadata blocks just for retention? If this trend continues, the small blocks will quickly outpace all other block counts. I would expect the metadata would grow a bit, but I would expect it to level off at some point.

Is this expected to have the under 1024 B objects grow continuously? Will this ever level off, or will this continue to grow significantly?