This is a very good proposal!I want to start a crusade that everyone interested in high quality audio reproduction should try a level-matched double blind listening test sometime in their lives. For me it was very enlightening and really helped my thinking about audio electronics. And made me a more relaxed and happier listener.
I can tell a similar story. Sometime end of the last millenium (after I finished my DIY preamp) I did some Opamp rolling on my DAC, an Arcam Black Box 3. I replaced the Opamps in the analog output stage by OPA2134 (the same I used in the preamp) and added 100nF film caps in parallel to all electrolytic caps (that was the hype back then). When I was finished I did a non blind test comparing the modified Black Box 3 with an unmodified model (had a second one used in our second system). Oh boy, what an improvement this has brought - more dynamic, better sound stage, veals lifted - you name it.I set up these kinds of tests for myself as a young adult using an amplifier switchbox I made. I took my switchbox to a couple of friendly audio salons that had very good speakers that were set up well. I compared a 70 watt JVC receiver and an 80 watt Sansui integrated against the TOL high-end preamps and amps they had at the salons. I couldn't hear any differences (a long as we kept volumes below clipping). The salespeople thought they could but they didn't do any better than random guessing and gave up pretty quickly. To me the lack of difference was definite and, well, liberating. I had heard very clear differences in sighted tests.
tl:dr I heard all sort of differences in electronics until I did fair blind comparisons. After that, it was clear that speakers, acoustics, and source material were a better place to focus.
The interesting part happened the day after, when I asked my wife to perform a blind test. I scored 8 of 10 right - so it may be statistically significant. But - it was extremely hard to hear any difference at all! This told me once and for all that I cannot rely on what I'm hearing, and the direct consequence was that I did not modify the second Black Box since the very marginal improvement was not worth the time and money invested.
The typical audiophile trusts his ears and usually argues that the human ear can hear things which science can't measure, thereby ignoring the fact that science has indeed shown that the human ear is fallible and the engineers can measure differences where humans fail in blind tests but not the other way around. There is a ton of scientific results showing the ability and limits of the human hearing sense (combination of ear and brain processing) but it is disregarded by audiophiles because they cannot accept that their sense may tell a lie. Maybe because one had to accept that a very costly investment in high end equipment might have been stupid.