IIS threads & best practices for APIs when integrated

This may be more of an IIS question than a PSU question, but I’m not sure where I’d ask the IIS question without being asked for more details than I know about PSU.
As I understand it, best practice is call scripts and whatnot when you have code that may take a bit of time to run so that you don’t tie up http threads in IIS:

Since I’m running PSU in IIS, I’d expect that calling a script as the practice describes would start another processing thread. Is the thread that script would run in separate from the http thread pool that we should avoid exhausting? Does the choice of Environment (Integrated vs. PS 5.1 vs. other) make a difference here?


Product: PowerShell Universal
Version: 3.9.2