If I do understand the various issues that have been reported it’s not yet implemented fully, eg the “startSession()” is one of the problems.
So my questions are:
Has anyone managed to find a workaround and get the multi-document feature to work in Meteor?
Is there a date for implementation of this new feature and a definite commitment from MDG to implement this?
I refer to eg the following closed issue: Upgrade to MongoDB 4.0 #269 for further reading, more references to issues are in that issue.