I use this knowledge to optimize how I work. When I'm songwriting, I don't edit, I just play parts and let ones I don't like stay if they further the development of the overall song. My "real-time engineer" is having enough keyboard shortcuts and facility with Studio One that I can "engineer" myself pretty much instinctively, so it doesn't interfere with staying in the right brain. After the tracks are down, then I do my editing, which is a left-hemisphere engineer task.
Well, there's so much in this one paragraph alone, I'm lured back in

Let's just say I agree with your basic premises, but feel compelled to chime in. Regarding writing and editing at the same time, as in not doing it, I completely agree on how counterproductive that is. However, while you mention editing—which, correct me if I'm wrong, but to me that means moving notes around or recording new ones till you're happy with a performance that's sung or played—I'd distinguish that from sweetening, which is reaching for all your EQ, compression, verb, delay, etc. tools to make that edited part sound better yet. For me, sweetening's the last thing I want to do when I'm struggling with, say, a guitar lead. Imagine there's a part you can almost play, you try slowing down the BPM, but it's still hard, and you're rethinking things...when then you notice you don't like the sound of the part. Now you've left one trouble area for another, and, more times than not, once you feel you've improved the tone, it's entirely possible that you've entirely lost the mood of the solo you couldn't quite play.
That said, you go on to explain that you've been doing this so long, you can sweeten and perform at the same time. Well, you've had a good three decades plus to perfect this technique. The op hasn't. I'm guessing, but I'm imaging that when you started out, you observed working situations involving engineer, producer, and artist before you tried your hand at all those skills yourself. I can't recommend observing someone else adept at doing what you want to learn to do highly enough.
It takes a long time to figure out how to wear one hat at a time when you're writing or recording most of a song's parts yourself. It takes a lot of self-discipline. It also takes daring to suck, and putting in the time investment to unsuck. The good news is that once you start proving to yourself you can suck and unsuck, you know you can do it even if you have to stand on your head every so often.
Regarding the workings of the brain discussion, while the information may be accurate, I'm not sure tuning into that is what's gonna jumpstart the op's recordings as much as looking into helpful co-conspirators, watching them in action if possible (remote will get the song done, but won't teach "how to fish" so the op can do it himself), and learning from them.
There's also the human ego's tendency to believe when you're struggling to figure out how to record songs to a standard you wish to reach that you're the only one who struggles, that it's somehow easier for everyone else, that people just start out and breeze through recordings. Those aren't helpful thoughts. Sure, some people are naturals at one of the aforementioned studio skills, but as previously concluded, no one skates through all of them without investing major effort.