The “default” form of the script is basically loading approximately 46,000 documents into an array, then writing those back over the network.
If you look at the script you will see a couple of
console.log() statements which would tell you what part of the progress is being made.
Depending on your internet connection speed, and whether you filled in the
projection or not ( which should reduce the document size if you do that ) this can take some time.
In short, “it depends”. For me it’s relatively quick ( even with a pretty high latency ), but mileage will vary depending on where you are in the world.