As longs as it can serve up the 'bits' to the DAC accurately and the DAC can accurately clock the samples, then the transport 'should' have no impact on the sound quality.
If you can hear an audible difference, then there is no other explanation for that difference, other than jitter in the stream is degrading the performance of the dac. If someone claims that a certain "threshold" isnt audible, then it is a subjective assessment in my opinion.
Like the claim that we cant hear frequencies over 20k. It's widely accepted now, that brickwalling audio at 20k makes an audible difference, whether you can hear a 25k test tone is irrelevant.
I'm happy to be blind tested on transports I am familiar with, any time.