A couple of details ...
the return of shared memory
> At the start of 2018, Shared Memory and high-resolution timers were effectively disabled in light of Spectre. In 2020, a new, more secure approach has been standardized to re-enable shared memory.
mondo details here https://hacks.mozilla.org/2020/07/safely-reviving-shared-mem...
more secure target=_blank links
> To prevent the DOM property window.opener from being abused by untrusted third-party sites, Firefox 79 now automatically sets rel=noopener for all links that contain target=_blank.