I did end up testing and using this by extending the service in my own project and it works well 👍

On another note, I also have an implementation that uses comlink and idb-keyval for some cool service worker based offline storage. But, it serves a bit of a different purpose and I am not resetting the store like the code for this PR does. It is more for "offline first" than "offline backup". For the app that it is implemented in, everything is kept in memory for speed purposes. I left the actual methods (and filtering the list) on the main thread due to how service workers can actually double memory footprint. But, the storage on the service worker size does a bunch of compression via compress-json and some other offthread niceties. Maybe its worth some ServiceWorkerService in this library.