I believe it would be good to explain a little more what this option does
exactly - "fetch information from the internet". What type of information will
not be fetched? What impact does it have on running windup/the analysis?

Is there a place in the documentation where we say what is "fetched from the
internet" when not turning this off?

If "not using" this option may cause issues for users (timeout, long duration,
freeze etc.), do we have the appropriate error information, or diagnostic
information (log statement) to see what exactly windup is trying to do at that
point, and what the failure is?