Evaluate whether we are suffering from MongoDB slow trains

[nathanielrindlaub]

More info here: https://thecodebarbarian.com/slow-trains-in-mongodb-and-nodejs

My guess is that we are not because we await all of the DB calls anyhow, so I think MongoDB is only be asked to do one thing at a time per connection anyhow, but it's worth double checking. If so increasing poolSize could be an easy performance gain.