As far as I could tell, when that function is called, it will begin downloading the resources in the list argument, but it will simply continue running the experiment. When I opened the browser console, I could see the files loading in the background.
The problem I kept encountering is that if you get to a point where a resource is called, but it hasn’t been downloaded yet, then the experiment will crash.
Yes I agree some way to query whether the resource was downloaded is probably the best way around this issue.