Bikes aren’t that complicated really, as such nuance of a scale imperceptible in casual observation can be picked up by an astute user. Ride enough bikes over time and one will pick up on the small factors that led to Bike A’s stability versus Bike B’s responsiveness or compatibility with this component platform and thought of the one thing falling short in A & B bike that you’d like to have imparted on bike C, the next one you are piecing together. This isn’t normal behavior, but it is out there and the bike junky nation is an educated lot so they know what they want when they ask for a bike.
Hence the Dossier, I need to do some reading before I draw.