About 15 years ago I bought a nice railroad pocket watch off of the internet. It ran fast so I took it to a watch repair shop in Atlanta Georgia. Their rapair technician put the watch on his timing machine, adjusted the regualator pins and gave the watch back to me. Over the next few days, it was running fast again. I took it back and the technician went through the same procedure. I took it home and and it did the same thing. I put the watch in a safe years ago and forgot about it. I never knew what was actually wrong with the watch until Watch the Bear had a similar problem. Through study, practice and observing the problems others have on these forums, I learned what these four screws are for and how to adjust them.
When I took my first watch course a few years ago the balance wheels that offered this adjustment were already phased out due to modern manufacturing methods and materials. The balance wheels made today are dynamically balanced and reweighted by cutting the wheels with lasers. This produces a balance wheel that is ustimately cheaper to manufacture and produces a better product. The problem with the process is the machines are incredibally expensive and are owned by companies like Eubache who make millions of watch movements. Since it is an automated process the factories get a tremendous cost reduction per watch.