You're changing the "BAUD" rate - like the speed on your internet connection. For each doubling in speed, you cut the time (width) of each bit of information in half.

Thus, very small variations in the electronics timing of each bit transition becomes far more critical - resulting in your cheaper units "missing a bit" of information here and there - causing the data validation to fail.

Delay times between polling PID's is likely not changed as that it is probably controlled by the microprocessor in the ECU and its communications protocol standard.

You're getting way deep there! But it is all very interesting.

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54371019

This option is about speeding up communications between the ELM-327 adaptor and the vehicle ECU(s), not between Torque and the ELM adaptor.
There is a facility within the ELM adaptor called 'Adaptive Timing', which seeks to automatically determine the minimum time to wait for a response from an ECU, rather than to always use the delay specified in the ATSTXX command.

The 'Faster Communication' option is used to tell the Adaptor how 'aggressive' the algorithm should be.
If you choose 'Faster Communication', Adaptive Timing will be set to Mode 2.
If you turn this option OFF, then Adaptive Timing will set to mode 1, and additionally, you'll notice that the option below it, 'Disable ELM327 auto timing...' will be enabled, giving you the chance to turn this feature off altogether!

The internal algorithms may not be implemented correctly, or indeed at all, in some ELM327 clones, hence the different results with this option ON on some adaptors.