The holes that you reference above, were all put in by the manufacturer of the product, not someone else. When it comes to a Baja vehicle, those are usually custom built by the user, and they are ultimately responsible to themselves for whatever happens to them and their vehicles. I have no knowledge of "slide cuts on competition firearms frames", but I would be comfortable in saying that those modifications were done by a licensed professional that has expertise in the field. You say "that a couple of holes in a ROPS will weaken the structure seems to be a thing made up by lawyers rather than engineers." is at best conjecture on your part. If you think about your statement, why would lawyers make up this statement, unless they could find an engineer to back up their claim? Lawyers don't push facts in a courtroom, unless they have an expert back it up. If you want to drill holes in your ROPS, go to it, but keep in mind, that you are ultimately responsible for your actions. If your ROPS fails in a roll over accident, you have no one to blame other than yourself. If you survive, you can try to find an attorney to take your case and argue that what you did didn't compromise the ROPS, but the ROPS design was defective, and that is what caused the failure, but the manufacturer will have lots of proof and documentation that it was tested, and certified to a specific standard before it was released to the public. Who knows, you might even find a sympathetic jury that will agree with your attorney, but it will be reversed upon appeal of the manufacturer.