There is another "theory" about the EJ ringland failures.
It's a big piston top, and flame front propagation is compromised. Add TOO MUCH fuel, which is exactly what most/all aftermarket tunes do for "safety," and the inefficient combustion leaves fuel in crevices... crevices at the perimeter of the piston. Add in the inevitable circumstantial detonation event... and there goes the ringland.
In short, ringland failures are more to do with AFRs and timing than bad pistons. LEANER AFRs are safer in the EJ than richer AFRs. My opinion, and one I successfully followed when tuning. But the initial idea came from someone else years ago. It is tuning, and specifically BAD tuning, that has made a mountain out of the EJ's hypereutectic ringland molehill. (All due respects to the engineers assembled here.)
The FA20DIT has addressed this "issue" multiple ways. The piston top is smaller (and etc), the piston top is shaped to maximize combustion efficiency, and direct injection applies the exact measure of mixture precisely where it can ignite and propagate efficiently and completely. No more can of fuel dumped into the combustion chamber and crowbarred into some semblance of power with timing by the unknowing.
YMMV
