I remember the jetstream 31 was a handful at low speed when the rpm was changed due to the different response time of the left and right engines. Quite a lot of aileron input would be needed during changes of thrust
well, thrust ( power) changes on the tpe331 will not result in any rpm changes on this single shaft engine.
beyond that a small mismatch in torque as well a slightly different response time is everyday business, every aircraft has a small mismatch , even with freshly calibrated engines.
for me it seems that they came to high and tried to reduce using beta inflight, lost control and stalled out . the small response difference when they at last second applied power again is not the reason for the crash in my opinion.
best regards