Bill Tindall, E.Tn.
I would have liked to see the test done on the steel most people use Hock or Lee valley O1.

I will have go find the paper where the work is described, but K&K found 30 degrees optimum and 35 degrees substantially worse (I think I recall).

How common is 35 degrees for a plane blade? If 30 degrees is typical there is probably a reason 30 degrees is typical.