How are ServiceWorkers and ServiceWorkerContainer.prototype.register, used for fingerprinting and bot detection

I often see websites that have advanced bot detection/fingerprinting technology that make use of ServiceWorkers and/or ServiceWorkerContainer.prototype.register. I'm not sure what exactly they do with it. There is also a chrome extension, Dont FingerPrint Me, that claims ServiceWorkers are used for fingerprinting and provides a feature to detect when a website does so. However, it doesn't explain how they are used. I've tried understanding it by reading the code, but did not get anywhere.

So, my question is, how can that be used for fingerprinting or detecting bots? By bots I mean browsers automated via selenium, remote debugger, or some other automation tool.

Edit: Unfortunately, atm I don't have any links saved of some sites I've previously come across that are using this technology. If I find one again I will update the post.

Edit: I was told that they can be used to bypass fingerprint blockers a browser might be running and to detect spoofed properties. I'm not sure how valid this information is however.

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