Looks like they are made plenty stout for the application. Cast Pistons are very common. Forged Rods are the thing that concerns most on an HD Build, and it looks like the Roxor has Forged Rods.
A serious off road build is about the only application that I can see where HD Parts might be needed. Max is our Hero Off Roader. I have read his build post end to end over the years. I do not recall any engine internal modifications, and his Roxor has the power upped a lot.
My normal driving sees my Roxor up to 2500 RPM's once in a while in the lower gears accelerating. My normal road RPM is around 2,000 RPM's. The Maximum RPM on the 2.7L is 2700 RPM's. I do not Rock Crawl or Race my Roxor. Keep the maintenance up, and take care of it, and It should last for many years.
Bob R