The milled trigger guard is superior to the light stamped version, and is always used on competition #4's. Milled guards as you can guess stay put in a glassed action or when they are re-enforced with additional soldered steel. On run of the mill Ranger service rifles that get heavily used I can see the advantage of milled guards. As for safety problems, the catch and the spring get worn and can easily be replaced.
I have been on the range with the West Coast Rangers and did some tech. work for them too. I know some their rifles are near the end.