You make your choice and you try your luck.
I spent a lot of my youth and early adulthood putting together motors with highly questionable parts - sometimes it worked well, sometimes it just worked, sometimes it didn't work at all... But it did give me a pretty solid understanding of what really matters, compared to what makes people feel good.
If I owned NSR's piston, I'd prefer not to use it - but if it is hard to get a better one, then I'd fit it and wouldn't have a moment's worry about it causing me any problems.