Well, yes, quite a few were indeed shut down for a variety of reasons.
PRT's would overheat, oil pressure would reduce unexpectedly, props would become uncontrollable, etc.
The CurtisWright turbocompound engine especially.
This particular engine produced one HP
per cubic inch of displacement, about all that could be expected of any design. The fuel consumption for this particular engine was 0.36 pounds fuel/HP/hr, when operating in high blower at altitude.
Normal for others was 0.50 pounds fuel/HP/hr.
The engines on the Boeing Stratocruiser were unique as well (Pratt&Whitney R4360's) as they used a supercharger (blower) as well as an externally mounted General Electric turbocharger, for improved high altitude performance.
These engines were developed especially for the B36 long range bomber, and could operate successfully at 40,000 feet. Of course, on the Stratocruiser, the authorized operating ceiling was 25,000, due to passenger oxygen requirements.
If you are ever in the SanFrancisco area, take a side trip to the San Carlos airport, to the Hiller helicopter museum. They have a cut-away rotating model of this engine...very interesting to see.