Noel,
In my view that is a terribly flawed concept if it is suggested to developers as a "better option"
How it fits in your philosophy that a new comer would open picker and just type “sw piano 85"?
I assure you this would not happen. In fact, most likely it will discourage that person to explore. Most people like to browse and choose, not mooshroom hunting.

You are basing your answer on your knowledge of program, your knowledge on track specific items, your knowledge of types of instruments etc.
And that works for you. That is great. But even your avatar shows you have been around for 12+ years, and probably longer. Somebody,.I forgot who, said something like: Good technology is when you can fully use it without a manual. I am simply trying to think this in terms of "wider audience" (myself included).

Does main RT picker have issues? Sure it does, but unlike "filtered" it has a straight forward approach with many searchable and sorting ways.
I see no benefit in the "new" picker, only disadvantages. If a few "filtering" options are in a way beneficial, perhaps it is a good idea to tune main picker at a later time (2022 feature #25?) to add some missing filtering capabilities. I have seen requests on the topic and I am pretty sure they were related to main RT picker. But...if the new picker stays, it might be harder at a later time to re-route it and amazing new feature of extra tracks might become yet another "performance" track item that is unpopular and hardly ever used by anyone, because it will act completely differently from everything else. Noel, think unifying, not fragmenting smile