Which use case/requirement will be addressed by the proposed feature?

Embedded use cases will be able to track progress through empty LSN ranges while the connector catches up to the current LSN. Currently, if you rely on heartbeats to indicate progress, you'll probably time out and kill the engine and no progress through the empty LSN ranges will be recorded.

Implementation ideas (optional)

Calls to SqlServerStreamingChangeEventSource.executeIteration() which output no records should also update the change position in the offsetContext and dispatch a heartbeat event. I'd be happy to contribute this, if it seems like a reasonable approach.