I think it's contradictory to exchange prefixes via DM if you consider it a useless search. In principle, it would even be illogical to search for prefixes if they think that way, and even more illogical to keep them as something valuable if that's their belief. Are there doubts? Or is it simply to avoid giving a possible advantage, no matter how remote, to someone else?

Still, I think it's a bit silly to focus on puzzles now in the conventional way. We have competition using farms for both 135 and 68. Although we have statistical advantages with probabilistic methods, we cannot compete against a colossal brute force. That's why I share my ideas, whether they seem good or bad, it doesn't matter. This is just a hobby for me at the moment. The real candidates to succeed are the new "puzzle miners".