The following uses of maxTimeMS are not currently covered by jstests, but should be:

• Test that mongod properly sets the leftover time on the aggregation cursor, if a cursor needs to be saved for getMore.
• Test that mongos properly propagates maxTimeMS to the shards (for an aggregation on a sharded collection).
• Test that mongos properly propagates maxTimeMS to the primary shard for the merge operation (for an aggregation on a sharded collection).