This is marked as RESOLVED FIXED now which means the [MDN page] (which links this bug) is outdated.

  requestIdleCallback

is now cross-browser. At least... technically.

I could only get it to work on Safari Technology Preview. But [looks like] it should be landing soon. Seems to just be blocked on high CPU on [ARM 7].

[MDN page]: https://developer.mozilla.org/en-US/docs/Web/API/Window/requ...

[looks like]: https://bugs.webkit.org/show_bug.cgi?id=262551 and https://github.com/WebKit/WebKit/pull/30619#issuecomment-222...

[ARM 7]: https://github.com/WebKit/WebKit/pull/34182