Both issues seem to have known workarounds that could have been integrated to support JXL on iOS properly earlier than by waiting on Apple (who integrated JXL i

Both issues seem to have known workarounds that could have been integrated to support JXL on iOS properly earlier than by waiting on Apple (who integrated JXL in Safari 17 apparently), so if anything that's a success story for "provide polyfills to support features without relying on the browser vendor."