I thought I would wait until your basic question was answered before interjecting this. Brian Burns has written a very good short book about double bevel sharpening. Brian is a guitar maker, who has to work with wood subject to a lot of tearout. He has developed (not invented, he traces the idea back to 1825) some fine sharpening techniques using double bevels (the second bevel being on the back of the blade).
His book discusses bevel angles for planer and jointer blades, including how to determine the angles. his website is: lessonsinlutherie.com
The book is about fourteen dollars, including postage. Brian is good about answering emails.
I believe you would find his book a useful reference. A recent article in Fine Woodworking referred to Brian's book, but merely scratched the surface. The book has a lot of good information.