Ray sounds like a solid dude. Some people guard their tricks because they think it keeps them needed, but the good ones know that lifting up the people around them does not cost them anything. As for why he picked you, probably he saw someone who showed up and did not complain, since that is who leads remember when they get a chance to help. Those twenty minutes changed your whole year and he likely never thought twice about it, which is kind of the best part.

My old line cook Marcus swore by this at the diner where we worked back in 2019, and he'd add the salt the second the water started rolling, not before. He said cold water takes forever to dissolve the salt and a lot of it just sits on the bottom of the pot doing nothing. I started doing it his way and my noodles did taste more even, not salty in one bite and bland in the next. The thing is, 30 seconds of boil time does change how fast the water moves and how the salt spreads around, so your test makes sense to me. Your sous chef might be right that the end result is close, but close is not the same as the same, and you noticed it. If your taste buds and your timer both say it works, keep doing it and let him watch.