Moving the code to IRAM might help, but really the high level HAL function probably compile to 1000 machine instruction, because they setup everything, every time.
For lowest latency one would have to prepare SPI configuration and DMA configuration beforehand and then only toggle the DMA enable bit.

While the code does not show any error checking, I checked the relevant IIR functions and all of them would print an error log, if there was an error. There is no error log output.

Is anyone successfully using the ADC filters on the esp32s3? I supply a constant voltage to an input pin (GPIO 8 - ADC0) and measure the same standard deviation of the converted ADC values regardless of the filter setting (0/1/2/3/4/off). I am using the continuous mode driver. The conversion values ...