On one of the last clients I have worked, I have implemented dbachecks in order to get the state of art and know how cool or bad the environments are before start knocking down the bad practices.
This client has seven different environments with more than 100 instances and more than 2000 databases.
Serial execution
A non-parallel execution (single session) took more than 2 hours. This is not a big problem when we run it out of hours and we don’t want/need to be looking or waiting for it to finish. I set up it to run at 6 in the morning and when I arrive at the office I can refresh the Power BI dashboard a get a recent state of art.