Reground Fiat TC 2 liter crank?

[tricky]

If I may add a quote from the delta integrale factory workshop manual, covering all models 8v and 16v . . .

In order to improve it's endurance and wear resistance properties, the crankshaft has been subjected to a nitriding treatment.

When the crankshaft is re-ground, after the main bearing jounals and crankpins have been machined to undersize, the crankshaft will have to be re-nitrided to prevent it breaking during operation. It will be necessary to refer this job to a specialist workshop, specifiying that the treatment is liquid nitriding. After treatment, the crankshaft must not be straightened again, although it must be checked that the distortion is within specified limits, otherwise the shaft will have to be replaced.

I read a rumor (somewhere on the internet) that the process of liquid nitriding is is banned amongst OE manufactures for whatever reason, maybe enviromental ?