Then you have people like Floyd Toole and Sean Olive who strictly evaluated sound quality in their research using proper time synchronized quick switching double blind tests but are subjectivists. All of their studies were based on listener preferences. All scoring of their tests were done with subjective ratings.
No, they didn't. You keep repeating it as if were fact or it will be since you use it like a chant or a mantra. If you'd look up that conversation Darko had with Paul Barton (who was part of the team of Toole, Olive and others) you'd stop saying that. But you won't so here's a link to that conversation.
They used the exact same speaker positions so all the room reflections would be the same so there had to be a pause to swap out speakers. No synchronized quick switching. You can quick switch with cables but that would negate what the masters learned about human hearing and how our brains work. People need time to adjust to properly ascertain what they're listening to.
I was off a bit on the length of the listening sessions as they were of 20 minute durations and not half an hour. 20 minutes spent listening and 20 minutes spent not listening. The podcast is a great listen and worth anyone's time.
All the best,
Nonoise