Even before cameras, you could go in with a pre-filled ballot and go out with a blank one. All someone needed to verify paid votes was one ballot per polling station (or 2 if voters get 2 ballots).
The page you linked to says "How do you get Shenandoah? This garbage collector has officially become part of JDK only since version 12 and is available in AdoptOpenJDK 12 builds."
> and introduces memory overhead to every object for a forwarding pointer.