Not long ago one of our club members lost his steering when the rubber mounts broke. He restored his car from a basket case and had no idea about the safety bolts. Turned a corner and nothing happened.
He wrote an article in one of the magazines.
Bear in mind that turning the wheel with the car stationary will put a lot more stress on the rack mounts resulting in more flex, that wouldn’t occur in driving conditions. It shouldn’t move a whole lot even if the rubber has fully delaminated. The safety bolts allow float but just a bit.
That said, I switched to the poly ones about 4 years ago and they feel great. With our rutted concrete freeways I wouldn’t put solid ones on. Enough of that gets transmitted through the wheel as it is.