Sorry to bump my own bumping of an old thread (then again, no one else is here so why not

)
I just had a thought. This isn't like a serious theory that Im going to stake my reputation on, just an interesting possibility...
What if the "fact" that SMiLE sounds too overwhelming on psychedelics was itself the reason Brian pivoted to the Smiley aesthetic? What if, at some point, he listened to the music he was working on while tripping and was like "nah man, this ain't it, I wanted to make something that would
enhance the psychedelic experience--not overpower it!" Then that inspired him to go in a quieter, mellow, understated direction for Smiley? Again, there's not any direct evidence of this, so I'm not going to die on the hill that it happened, but it's not impossible either.
It's still completely up in the air how many times Brian took acid and when. We know the first was pre-California Girls, we know the second was a scary fire bad trip at some point pre-Fire (probably pre-SMiLE, maybe even pre Pet Sounds), then it gets murky. Probably the most popular understanding is that Brian did it one more time, Tobelman would say in Big Sur and it involved the pristine elements as a conduit for God. Danny Hutton thinks Brian probably did acid the night before he called him in to hear a session of GV (date unknown, sometime in summer '66). There's a Carl quote about Brian doing it a few times during the GV/early SMiLE period and never being the same after. David Leaf's original book claims Brian did a bunch of acid AFTER SMiLE to cope with its demise (this I don't believe). It's one of many details that can never be pinned down, where the more sources you gather the murkier the story becomes, where we'd like to think if we could just pin it down to specific calendar dates it might explain everything...
No one specifically says Brian tripped in, say, December through February, where interest in the project gradually waned. That'd be the most likely window for him to listen to his work in progress on acid and decide it was a detriment to the feel-good spiritual experience he intended rather than an enhancement. But there's no way to know for sure. Cam Mott on the other forum has said that Brian eventually listened to what he'd been making sober for the first time, since the early sessions were a haze of constant hashish, and thought "nah, I don't like this, without the drugs it just isn't that good." That's certainly possible but unprovable and not something I can specifically recall from my research. I think it's just as likely though that it may've been the other way around, with harder drugs facilitating the change in perspective. (I mean, Brian couldn't have been stoned 24/7 right? He's always said to have been totally professional in the studio--he must've been more or less sober while recording the music and at home at least some of the time.)
Just another angle to consider. Carry on.