Safari on macOS and iOS both have "full support" for SharedWorkers https://developer.mozilla.org/en-US/docs/Web/API/SharedWorker#browser_compatibility and we have an app which uses a SharedWorker but when running in Safari we've yet to find a way to inspect the worker like you would in Chrome with chrome://inspect#workers. Upon further inspection, this was true of Safari dev tools itself and not just Inspect.
From Customer