I really like this idea a lot. I choose not to eat eggs or dairy so I bake without them -- I like the idea of having ideas on how to substitute these best in recipes "if" I should choose. If butter or milk is mentioned in a recipe it would be nice to have the absolute "best" alternatives mentioned whether it be a ground flax seeds or Ener-G Replacer for eggs or Earth Balance or canola oil for butter (every little bit helps). Also when using alternatives it would be nice to know if it actually changes the hydration of the final product (ie. oil instead or butter). I think these all would be good references to have in a future publication.
I find this bothersome. I have dietary restrictions. It is MY RESPONSIBILITY to figure out the correct substitutions, not the responsibility of the author of a Bread or Cookbook. As for giving the "best" substitution, what is "best"? What works for one person may not work for another. A lot of folks use sugar alcohols as a sugar substitute. They do nasty things to my G/I tract. So while maltitol may be the "best" for some folks, it is very bad for me.
I go to baking and cookbooks for the expertise of the author in baking or cooking, not in dietary substitutions. When I want info on substitutions, I go to those with expertise in that area, then extrapolate to include those substitutions in the baking or cooking recipes from other authors.
Yes, it takes a bit of experimentation. Yes, there are 'bricks' on occasion. But I don't see why Peter or RLB or any other author should have to try to accommodate people's dietary restrictions while they are trying to convey the process and methodology related to their own area of expertise.
OK, I am stepping down from the soapbox now......
Jan