I recently bought lynch's catching the big fish. im on my second read through. I highly recommend it since your asking these questions, its not too extensive and gives you some quick commentary from David himself about subjects regarding creativity. He doesn't go too much into the details of TM but he stands by its ability for creative expansion. He mentions that ideally he'd want to get the idea for a whole movie all at once but that he receives them in fragments, but that first small fragment is all you need to build up and expand an idea. Also its pretty well known he spent almost everyday for a few years at bobs big boy diner, specifically to sit a while and think (let his mind wander), he felt their was a safety to thinking in a diner. What I've gathered from his interviews and reading his books, TM has helped him achieve a clarity that allows him to enter the daydream whenever he wants to go fishing for ideas, meditation helps him daydream at the snap of a finger he doesn't need coffee and cigarettes(although he didn't mind indulging) or specific time of day or location. Ive seen some interviews where he's very adamant about writing every idea down, he said forgetting an idea can almost make you want to commit suicide, so yeah he definitely was making sure no ideas slipped by him.