Inconel is a trade name for nickel based alloy, much like Panadol is trade name for acetaminophen. There are might millions of inconel turbine wheels for diesel.. but not for gasoline engine it is still very relatively rare.

It doesn't make much of a difference in rotating assembling, but it makes a lot of difference in complexity and reliability.. also the final system weight.. eg you don't need a wastegate and a more compact packinging... things that Porsche cares.

To make spool faster is the lower the PSI.. make the whole thing smaller.. yes it has nothing to do with the nickel, but if you look again what I wrote, I didn't say that.

Which other turbo that can handle 2000F as you mention that is commercially available and for gasoline engine?

My work makes ~1000 turbos per month and sells more. All inconel wheels friction welded to 4140 shafts. Used on gasoline and diesel engines.

Most failures are oil related, or ait filter related.

Holset 351ve vgt most commonly found on the 6.7L cummins has been used on gas applications (not by oem).

I think we are talking apples and oranges. I'm just saying that inconel is not new to turbos or rare. Maybe in the vgt/vnt system it may be but not turbine wheels.