NSFW - I think enough guys on here have been running well-tuned cars at 350-400whp to show that stock pistons blowing at 270whp are more likely due to the tuning.
I've shown myself to be a worry-wart, and all I can say is that I find it extremely unlikely that stock pistons on a stock car in a good state of tune running 92 or 93 octane....well, I think they are fairly safe. I'm going to switch back to a OEM air filter (from AVO) to not push my luck.
And, to your point, the stock pistons + a reliable aftermarket turbo + an opened up downpipe (to help the compressor remain stable + a nice conservative and rich tune = a long-life, reliable LGT. In my mind at least.