If you modify your own ROPS, then who is going to sue who. You couldn't very well sue yourself. Someone who modified an ROPS at the direction of the owner would only face limited liability for the work done should it break at the reworked area which is highly unlikely since even a bad weld is usually stronger than the steel it is welded to. I just don't see the lawsuit angle as being a reason not to modify and ROPS if it makes it usable vs not using it at all.
If your theory is correct, one could sue the manufacturer if you didn't use it and had a roll over because it was not raised due to garage door height. One might file a suit like that (as you say anyone can sue for any reason) but it wouldn't make it past the judge. Similar to not using a seat belt and suing the auto maker because you were injured in a crash, not going to happen.
This is what scares me, Here in the US we have so many rules and Regulations to follow if you're going to be modifying Rops.
It has been made too big a deal here in the US not for people to sue. It would be like messing with seat belts or air bags. It would be hard to sue a homeowner doing what he wanted to with his tractor but if a Kubota dealer started customizing Rops?
Can you just picture the ambulance chaser asking for your test results that you did on the Rops modification. Just look at the test procedures at the bottom of the link.
c) Labeling.
Each ROPS shall have a label, permanently affixed to the structure, which states:
(1) Manufacturer's or fabricator's name and address;
(2) ROPS model number, if any;
(3) Tractor makes, models, or series numbers that the structure is designed to fit; and
(4) That the ROPS model was tested in accordance with the requirements of this subpart.
29 CFR 1928 : OCCUPATIONAL SAFETY AND HEALTH STANDARDS FOR AGRICULTURE [ 29 CFR 1928 ] : (LABOR [ 29 CFR ])
Does this mean if you're a homeowner without employees you can do what you want to your Rops?
Maybe, but I would not want a few modified tractors for profit under my belt out in the field.
I think these regs are for if the tractor was used in agriculture with employees. Can a home owner do what they want to their own tractor?
I believe they can.
But the homeowner paid a busness to do it. Then a video was made to show others how to do it.
Lawyers today sue for a lot less then death from a tractor rollover.
We all know that it is as strong or stronger then the original and no one will ever die because of it failing. but look at the regulations about Rops. on tractors.