MongoDB has a 16MB limit per document hard-coded, since eventhus uses a single document to store the events, there's a limitation there.
I would recommend using per-document events, instead of per-document aggregates, and you can still make that atomic by simply removing the if condition here and remove entirely this else statement.
Of course, a change to Client.Load() to do a findAll instead of findOne, and sorting by the version later. What you guys think?