The addition of the "Ignore Prefetch" is a great update and I'm already using it. Thanks!
On another site where I control the code, I don't track either Firefox Prefetch or Safari Preview, as they both involve involuntary page views. In my experience, Preview especially made my bounce rates on Google Analytics much higher when I was letting those page views into my tracking.
Technically, this is easy to do. Just check for the X-Purpose header being equal to "preview", similar to how you check the X-MOZ header being equal to "prefetch".
I've also recently asked the developers of the two leading GA plugins to implement these tracking filters. So far, they haven't responded, but at least you have half of it covered already, so that's good.