Oh, that's an excellent point, especially since this is a perfect case for workers more broadly. I've had a bit of an app dev interregnum these last or postpandemic years; if service worker support has advanced that broadly, then that's wonderful news! Not especially surprising news, I suspect, but wonderful. Last I afforded close attention, the state of play for service workers in iOS Safari particularly was "don't bother."

Since I like an iPhone - or have thought at least they're least worst for 13 years and counting - you can probably imagine how this would have depressed my interest: Even though irrelevant here in that touchscreen PDF editing is an extremely hard problem and none I'd expect a solo dev to address, just knowing nothing I built with a worker I would myself be able to use, has made me not want to sink good time and effort into the topic at all. Best case that's all just wasted; worst case, it creates a dilemma I might not escape without a new regret.