In the recent piece he did on Taihaku Priest (RIP) and her teacher, Tanaka Shinkai, Taigen Dan Leighton wrote:
I did a handful of sesshins with Tanaka Shinkai Roshi, Taihaku’s teacher later at Hokyoji, the training temple founded by Dogen’s Chinese disciple Jakuen near Eiheiji. Earlier as a young priest, Shinkai Roshi had been invited by Shunryu Suzuki Roshi to come to SFZC to help, as he invited Katagiri Roshi and Kobun Chino Roshi. At that time Shinkai Roshi had to decline the invitation as he was leading the Tokyo branch of Eiheiji.
That was news to me. I put it in a notes section for the up and coming greatly expanded Notes on Crooked Cucumber to add to the list of those he was considering that we knew about - Kosho Uchiyama, Kojun Hakusan Noiri, Rempo Niwa, Yuho Yokoi. I don't know if he actually asked any of them as Taigen reports he did with Shinkai. Those were all heavy hitters. Maybe Shinkai would have worked out but not the others I don't think. They were too established and had their own way. I think who did fine with who we got - Kobun Chino, Ryogen Yoshimura, Sotan Tatsugami, and at the very end, Ryuho Yamada. Dainin Katagiri was already one of us.