I have a feeling that I would like and get along with Mr. Singh if I knew him personally. My kinda guy!
I think the reality of the situation is that the auto Mfrs. have spent enormous amounts of time and money developing and testing flame propagation in combustion chambers. I'm sure engineering and testing of this situation is a high priority [emissions , fuel economy, more power from smaller engines].
I'ts hard for me to believe that many similar ideas were not engineered and tested. This goes for the racing community, as well.
I don't think they know that grooves in a piston would help immensely, and then not utilize the concept!
Mr. Singh may not have a worthwhile idea.