Mixing multitrack was probably my favorite active audio activity. Fast switching via the solo,group and recall (on boards with automation) functions was the only way to actually be sure those tiny adjustments were real, worthwhile and not imagined (like accidentally making an adjustment on the wrong channel strip LOL Hey, it happens!)
Now I wouldn't call this doing things blind nor do I think it should be approached blind but rather pragmatically. There's a sound in your head, an expectation if you will, that you're trying to translate into reality. Fast switching many times is needed to tell you if you are getting closer or nearer or whether or not the "eureka" moment is really "all that".
I understand that from a fidelity point of view any deviation from the signal is a no-no. I just want to inject into the discussion some insight on how the signal came about in the first place. It's the result of a long chain of human decisions from the pen of the composer to the QC dude at the pressing plant.
So my personal position on the argument is that:
I disagree with Frank that fast switching will not yield anything worthwhile.
I disagree that blind is the way to go for tuning or system setup. What's needed is a firm grasp on variables and the environment so one can get consistent, repeatable results even if the subject is yourself. This requires being able to go back to the starting point if need be for the all important reality checks.
I do not disagree with the philosophy of ultimate fidelity to the signal. I just do not adopt it
in toto but rather
In toto et pars continetur. In other words, I will knowingly deviate from as flat as I could get it to something else whenever I want to. This also means I can go back whenever I want to as well (see above) hence the
"et pars continetur". I put myself and my reactions to the signal into the premise making BOTH the signal and myself part of the whole. This puts me in line with Micro methinks.
I have absolutely nothing against doing things blind. If you can't hear the difference, go with whatever's cheaper. If you want to buy something that costs more just because it looks better, I'm cool with that too. Just know that that is the reason.
I have nothing against expectations or expectation bias. Life would be boring without it. Success is always sweeter the harder you have to work for it.