You can go here and do the following:
Click “Tower Levels” and type “rock” into the search bar. I also recommend displaying 50 entries.
It looks like a nice bonus amount of honor shards on the second completion, so it’s probably a situation where we want to clear it on a secondary character, or the one we care least about that we can comfortably clear with.
This also provides us with missing skill points.
Specific rewards could change, but I doubt it.