Trio for Blunt Instruments

The story's twists and turns kept me on the edge of my seat, but I wonder how much planning went into the puzzle. Did the author plot every clue in advance or discover it as he wrote?

The witty exchanges made the story more engaging, but I’m curious if Stout always intended that contrast or if it developed naturally during writing.

His unique personality and methods stood out for me, but I wonder what inspired Rex Stout to create such an unconventional sleuth. How has Wolfe influenced modern detective figures?