<a rel="opener noopener" target="_blank"> should create a window without opener, as per: - https://html.spec.whatwg.org/#get-an-element's-noopener (noopener is checked *before* opener). Firefox and Chrome match the specification.
Created attachment 435367 [details] Patch
Committed r280933 (240450@main): <https://commits.webkit.org/240450@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 435367 [details].
<rdar://problem/81816188>