Is there any reason to make a Poolish or biga exclusively with AP flour? Is there any reason I wouldn't want o make either with a blend of flours?
In most of the formulas I see they are most often with bread flour. But for flavour optimization one might want to blend flours.
https://www.weekendbakery.com/posts/more-artisan-bread-baking-tips-poolish-biga/
It has a lot of other useful tips and advice for making a polish as well. A good read.
I never even considered looking there. Much appreciated.