Implement operation to check if documents in collection have changed

Is there a way to let users determine "has db.myCollection changed at all since <time>" that is more lightweight than opening a change stream and listening for change events?

It would be useful to be able to check if a collection has changed in any way since some time.

Motivation

The atlas search "synonyms" feature defines synonym data in a user collection. Search automatically detects changes to that collection, and updates synonyms artifacts on change.

Search uses change streams to detect changes to that collection today - but does not have a way to incrementally modify synonym artifacts given change event information. mongot must replicate "from scratch" on each change.

Change streams are an effective way to detect a change for a collection - but, if possible, we would be able to ask "has this collection changed?" in a less resource-intensive way.