Why does innerHTML assignment NOT create a shadow root from a <template shadowrootmode> string, while DOMParser.parseFromString with the right option does?
// case 1
el.innerHTML = '<template shadowrootmode="open">x</template>';
// case 2
new DOMParser().parseFromString(
'<div><template shadowrootmode="open">x</template></div>',
'text/html', { /* ... */ }
);