For the moveRange command, we may specify only the min key or only the max key to allow the balancer to identify the exact range to move. For some scenarios, we may want to know the exact range that the balancer moves. It would be nice if the result of the moveRange command can return the range that has been moved successfully.

For example, mark.helmstetter@mongodb.com raised this scenario when we try to move a specific chunk off a shard. The chunk could be large as chunks are no longer split automatically since v6.0.3, so we don't want to specify both min and max to move the whole chunk in one time:

It looks like I can repeatedly call moveRange for the chunk(s) I want to move, but it doesn't appear that there's an easy way to know when all of the ranges have been moved for a given chunk, other than maybe constantly checking the chunks collection to see if it was reassigned to the target shard.