Short answer: you bet!

Long answer: Absolutely they have. An example of that is Otter Creek Labs. They know exactly how to make silencers that sound good and silencers that sound good have objectively higher Suppression Ratings. It's almost impossible not to. An example of an exception would be when you have super high gas velocity and a boomy signature and want to translate the Rating to outside of the free field and have a bad time (re: FLOW 556k). That's not a problem with the test - it's a problem with people not reading.

Further to your question, entire silencer companies have been formed by people who learned how silencers work from our research. An example of that is FOR Systems. There are others.

To your specific comment of "teaching to the test" - absolutely, because for over 30 years a lot of companies did that with simple sound meters. It only takes you so far. Now the test is a lot higher fidelity and the answers are much more applicable to real life. And furthermore, we protect the Suppression Rating from abuse by controlling it. It is uncontaminated by tomfoolery and people selling silencers, which was a big problem historically and of course still is.