Chrome plating is a nasty process and has been greatly regulated in many countries because of the human and environmental risk of waste material. I suspect that fact when coupled with economic factors of the reduced supply and requisite increasing prices are forcing the engine makers to move to nickel (itself a fairly nasty process, but not as bad as chrome) and other processes.

Most of my engines are ringed, so I don't sweat it. I only have an OS 61FX ABN engine left that I fly regularly. The miniscule loss of power of a ringed engine over an ABC/ABN equivalent is not worth it to me, plus I like to run all synthetic fuel.

I'm wondering why the glow guys haven't moved to Nikasil like the small gas engines have. Perhaps it's only compatible with steel liners and ringed pistons versus the ABC/ABN interference cylinder design...anyone know?