A eutectic alloy is one in which the alloy metal is in saturation with the base metal. No more will dissolve. Hypereutectic means you have too much.

I haven't heard of problems using hypereutectic pistons with nitrous or forced induction. I seem to recall instructions in some KB pistons for nitrous or forced induction for proper ring gapping, which is even more critical for hypereutectic pistons.

The biggest advantage of hypereutectic is lower piston expansion, which means that you can have less piston to bore clearance. I set up my (NA) Harley with about .001" clearance, which is about half of what I would need for forged pistons on that air-cooled engine.

I doubt that KB or Weisco make pistons for any Benz, but I believe that you can get custom-made pistons in pretty much any configuration. But note that if you lose fuel while supplying nitrous, you'll burn up any piston.