I ran into an interesting article on Sensei’s Library. called Shin Fuseki – for and against.
The article is very old (created in 2001) and based on a rec.games.go post by Fairbairn.
It’s a translation of comments made by strong professionals, in the 1930s, about shin fuseki.
The pros consulted included
- Shusai
- Segoe
- Iwamoto
- Maeda
and a bunch of others. Not the key figures of Go Seigen and Kitani, though (or Kubomatsu).