Working with whole wheat and rye
I'm a sourdough novice, and have finally been having success with loaves baked according to Alex's excellent youtube video (https://www.youtube.com/watch?v=APEavQg8rMw). This bread is at around 71% hydration with 100% bread flour. Now that I've been consistently baking nice loaves, I'm wondering how to go about starting to use some percentage of whole wheat or rye in my mix, or switching from bread flour to AP flour.
The first loaves I ever baked were using Maurizio's beginner's recipe, and although the flavor was stellar, I could never get my proofing time right or the dough strong enough, and ended up with a bunch of sad, flat loaves. I'd like to start getting back to that flavor profile, though, but am unsure if I should try subbing a small percent of the bread flour in Alex's recipe with some rye and whole wheat, or if I should go with a whole new recipe. How would whole grains or AP flour affect the recipe? (Gluten development, fermentation time, hydration, etc.) Any thoughts or suggestions?
Thanks so much!