That seems strange to me. It doesn't seem very unusual to me to use the "pro" laptop for actual work, and running a process that takes 20 minutes does not seem like a made-up use case at all. I don't know enough about fans to understand why they can't force more air through the laptop. My MBP gets too hot to touch when I rebuild a particular Docker image while the amount of air wafting out is not particularly impressive… but at least the machine looks good ;)