@Dr-GO you know my opinion of Jason Harrelson and his business practices. I do not consider his palette of instruments that adaptive. Sure, there is a lot to customize, I consider his approach to give a very „playable“ instrument but it locks the player into a certain shade of color. That is the bogusness of the concept. It is not what is in the players head, it is the shade injected by the maker.
This is my point. Those that buy those instruments do not „have to“, they simply can. The story comes after the fact.
I was with a student recently at a well stocked music store. The student was looking for a C trumpet. There were 6 instruments there, additionally I had my modified tuning bell Bach CL229H and my Monette Raja. For that student, a used Schilke screamed buy me! He sounded better with that instrument than with all the others. We had rehearsed auditioning instruments weeks before the trip. The student stuck to the audition procedures and was able to easily sift through the choices. We used my Monette as a reference but in the students case, it did not have that something special that the Schilke did.
I know of one manufacturer in Munich that has built „reference“ trumpets that are not sold or loaned. Potential buyers get a valve section and add parts with the goal of putting an instrument together that is better than the reference. They have a box of over 100 leadpipes -all essentially that all measure the same - but play differently. With the right audition procedure it only takes an hour to get the „best one“. Then comes the bell - much harder to zero in. At the end, braces are fitted. With another student of mine, we needed 3 hours to select the parts. This is what I was talking about. We got a horn that matched what was in the players head. It took 100 leadpipes and 10+ bells. This is NOT the Harrelson or Monette experience.
I can‘t speak for Harrelson as I have only played them but never bought one. In the case of Monette where I have 3, I can testify that the first one changed me. The second one was built on 10 years of communication with Monette and the positive experiences with the first instrument. He changed it. The third instrument is simply pick it up and play. There is no need to „think“ about color. It just happens.
The time frame needed to make musical decisions precludes „magic“.