Merely a thought,
But in a situation completely flooded with pressurised oil (surely must be one of the most oil-flooded parts) the issue of metal to metal aggravation should be minimal?
You would think so, but it depends on clearance relative to the viscosity of the oil. If the oil is free to pass down the side of the piston it isn’t going to do much in holding back the pressure, instead it would dribble down the side and start leaking off early, more so as the engine oil gets hot and the viscosity is at its minimum.
Lyford classics (A10 specialist) makes stainless bodied ball type pressure release valves. At the time there was a lot of hoo-ha about ball type being no good (before Dave maddigan did his testing on them) so I found some NOS piston types and fitted one of those. A while later my friend was suffering with the oil light on his OIF, we checked the oprv (SRM) and it was also galled, he fitted a lyford classics item and it solved the issue with the light coming on. The ball and spring are different on lyfords to the original BSA, the spring also looks stronger although I have never done a pressure check to see at what point it blows off.