GlusterFS and convoy-gluster have been a bit of a mixed bag for us. It has some users, but not a ton. And we learned that when most users deployed GlusterFS, they were expecting a robust tool for manage GlusterFS itself, which is not our area of expertise. Basically, we found the maintenance of GlusterFS to be too high to guarantee it as a Rancher storage solution. This is why if you look at Convoy NFS and Convoy Gluster in the catalog, you’ll see the convoy nfs is “certified” and Convoy Gluster isn’t.
We are doing things with storage however and are building a solution with all the features you mentioned (snapshot, remote backup, revert), but this effort is still under development. You can review that thread for some more details.