Some gleanings on turbo issues of that timeframe:
Dr. Sanford A. Moss (1872 – 1946) made the turbocharger practical, advanced the cause of gas turbines, and ended his long career by pressurizing civilian airliners.
While his work on turbochargers would earn him a Collier Trophy, Moss had a deep affection for gear-driven superchargers...the turbocharger gives better performance at high altitude [but] few people wanted to fly above 20,000 ft…[which] was both uncomfortable and dangerous for the aviator. Use of the turbo-supercharger has been limited to a few experimental ships and the most advanced Army planes. And though the
Air Corps engineers worked eagerly with Dr. Moss to develop the turbo-supercharger, it never seems to him that the tactical units made adequate use of its possibilities.
In 1937 Moss and his crew adapted the turbocharger to the YB-17, then considered obsolete. Within a year, the bugs had been worked out and the bomber flew faster than most pursuit planes. The turbocharger also made high-altitude strategic bombing possible.
As early as1931, NACA engineers recognized the superiority of the turbocharger at altitude As Oscar W. Schey wrote,
“[F]or altitudes of up to 20,000 feet, when ideal methods of control are employed, there is very little difference in superchargers from the point of view of net engine power, while for critical altitudes of over 20,000 feet an engine develops more power when equipped with an exhaust turbosupercharger than with any other type.
http://enginehistory.org/Piston/InterWarSCdev/InterWarSCdev.shtml