If I may interject something here. A while back I was one of the team assigned to investigate a fatal accident on a strip job. The operator had taken an old CAT dozer and made a ROPS in his shop, and I must say that it was a very good job the square tubing was hydro bent and the welds, and Im no welder, looked really good,, and the lab said they were good welds.
My point being the dozer went over an embankment backwards and flipped end for end, the operator was killed when a corner of the ROPS failed and he was crushed.
His wife is having a very hard time collecting his life insurance,, WHY??? because the ROPs had not been certified by a PE. If it had been then there would have been no problem.
So its just a thought you might want to do like I did after breaking my arm pushing limbs out of the way,, they all came off ROPs high