It would be great if we could:
1. Avoid hanging the inspector when the page does a sync XHR (use a separate process?)
2. Give feedback to the user that their page is stuck because of a sync XHR
If there's a bug for (1), then please mark it as blocking this bug, which should focus on explaining why their page is (sensically) hanging (not the inspector, which should never hang).
There is a radar about using a separate process for the Inspector, but not a bugzilla bug.
I think this is no longer relevant as Inspector is out of process, and a developer can easily pause the debugger or look at timelines if they think the page is hung.