Snapshot_tool not working/not fixed/maintained?

Upon configuring openwrt for build I noticed 'rootfs snapshot' tool in configuration.

Curious I checked what it is, and by looking at it looks like it's not working/needed/maintained part of fstools.

For example it's using /volatile/upper as a checkpoint, and SNAPSHOT=magic variable -> which are not proper/not working anymore.

as it's in the 'base' I think it would be worthwile to fix/clean it. If somebody points me in the right direction I'm willing to help with it.

found this commit on turris version of OpenWRT, may be it will help :

How this tool may worked may interest me also...!?

Also like to see docs on this... have compiled in a few times and it adds stuff successfully... never seen any docs on how to actually use it tho'