Depending on the map, I'll clear that in a regular rift after the RG drops. Like if it's a super dense open area. The reason I do regular rifts is mainly for DB's and GR Keys. I do GR's for shards. Shards are more of a bonus for me in a regular rift. So maybe like 75%-80% of the time I just reload, but I do finish a floor occasionally. If I get a cow rift I complete just because its so rare.
I had two this month, the only two I've seen since release!