I think YantraVR is Tony Davidson of
http://innervision-vr.com/
So he is unlikely to be making stuff up, but on the other hand neither do I think Sony have any "special sauce" to deal with barrel distortion.
My best guess therefore would be:
* I think Sony do have something in their SDK for Hidden Area Mesh Rendering. I think this is YantraVr's special technique.
* Sony optical warp is less extreme than OR and Vive so you can use a 1.0x render target at the developers discretion, but still less than ideal.
Damm, it would be good to know for sure instead of all this second-guessing.
This was posted at NeoGaf, seems less distortion on PSVR to my eyes BUT without them rendering the same scene its easy to fool yourself:
http://i.imgur.com/sMXBeWF.jpg
P.S. I'm not disagreeing with Mr Fox's statement above, just putting this out there to see if we can make sense of it