Might just be that more poolish = more flavour, as far as I’m aware poolish is only used by bakeries because they don’t have enough fridge space to ferment all the dough overnight. Baking at home, you usually don’t have that limitation. What I do is make the dough in the evening, and put it straight in the fridge, in the morning, I’ll take it out, and since it’s had time to autolyse, it’s usually very workable. Then I’ll do a couple folds over a few hours (keeping it at room temp) and throw it in the oven.
Another thing I noticed: If you usually use the same recipe as this, but without one of the poolishes, the hydration comes out to 72%, but adding another poolish will raise the hydration to 80% because the poolish is wetter than your base dough. Maybe you’re noticing the difference in hydration? I find that higher hydration usually yields bigger bubbles, a softer interior and a crispier crust.
Hmm, yeah, I didn’t know yeast messes up autolysis. I add everything in the evening and put it in the fridge, maybe it still works since the yeast takes a while to get going in the fridge. I also use cold water instead of lukewarm to slow it down even more, the goal is a slow fermentation overnight to get flavour and develop the gluten, while making sure the yeast still has enough “energy” for a rise in the morning. I guess you could also let the flour and water sit for a while before adding the yeast and salt and putting it in the fridge to make sure it really autolyses.
For high hydration, using high protein flour and letting the dough sit for a while before trying to work it really helps in my experience. Also, wetting your hands before touching the dough, but I imagine you’re already doing that.