What do you look for in a forklift?
I was at Clark when those tip over tests were done. We went to a "winged" seat that kept the operator in place, if they were wearing a seat belt. A seat belt alone has a tendency to whip the operator's head against the floor. We had a stunt man intentionally tip some over ("lateral overturn") with a helmet on.
Back to the LP tank, if I remember right (it was a very long time ago) forklift (and maybe other industrial tanks) are not like your barbeque grill tank. The latter feeds vapor, forklifts need liquid, which gets vaporized in the carb. So the two tanks have a different pickup location.