Maybe use the microflow timer widget: https://docs.mendix.com/appstore/widgets/microflow-timer
I think this is a good use case for a JavaScript action. Here’s how I’d go about it:
var link=document.createElement('a');
link.href=url;
link.click();
For S3 urls, I believe this will download the file vs. trying to render the URL directly. This worked in my quick test.