> Not because the page is buggy (it is, though, crashed on my iPhone),
Maybe you meant Safari is buggy and crashed? I can easily get Safari to crash by zooming in and out a bit. Reports to Apple go ignored...
Safari didn't crash. The web app did, for abusing the browser history API.
> SecurityError: Attempt to use history.replaceState() more than 100 times per 10 seconds
I get the sentiment. I don't love that different browsers have different behavior even on standards compliant code. But I've also done enough web development to know that if your page crashes safari in the main user flow (in this case, just hitting 'play'), the dev owns the bug.