Harness seams are an issue that every team has to deal with, and seem like the perfect way to improve safety by making it public so that other teams can judge how likely the same thing is to happen to them. At least this is something easy to test - figure out how strong your harness needs to be, go to the gym and start hanging weights on it.
At some point, the rules added a requirement for "professional stitching" of harnesses. Unclear what good that did.
At the time, people were curious about whether going forward into the hatch (as seems to be the case) or left-right into the shell broke the helmet. I would think most good teams pay attention to where the driver's head will go in a frontal crash and keep buggy parts out of reach. Unless someone is using head restraints, or has the helmet fitted into the shell, I don't see how one can keep the helmet from bouncing off the inside of the protective cage in a significantly sideways crash. That's probably going to go badly for a soft-shell helmet when the cage is made out of small-ish metal bars. The rules aren't clear on what they require in this case, since they all are in terms of applying forces to a _stationary_ cage.