Ap vs bread flour what’s the diff?

As noted, bread flour has more protein that AP flour, it is also high in gluten. Your waffles may end up chewier than you would like, but will probably be edible. If you're making them for your toddler, I say go for it. Cake flour is actually ideal for waffles.

Bread flour has a bit more protein, but/and can usually work well instead of a-p.
Sometimes it absorbs more moisture than a-p.
You might want to cook a test waffle and if the batter is too thick add some more liquid for the remaining ones.