I've just spent some time with
@JohnA1 playing with various configurations.
We tried a different power supply into his Qutest. I managed to detect a subtle difference but I wouldn't put money on reliably detecting a difference and I was of course trying to find the difference.
We tried my TT2 with his M-Scaler, both as a DAC and using the TT2's preamp, and I fully expected the same collapse of the soundstage that I get in my system but I really could not detect it.
It's possible that I am used to the sound in my system and therefore notice the difference when bypassed far more than in his system but I have to say that I wasn't detecting much, if any, improvement between the upscaled and bypassed sound. We spent a couple of hours doing this.
I was quite surprised. I expect that some of it might perhaps be that I am not used to the sound from his system but I did expect to hear at least some difference. I cannot say that I would reliably be able to pick out the upscaled sound, even using my TT2.