Problem resting/proofing shaped loaves
I've been baking for a couple of years but got serious about it and switched to sourdough a few months ago so far things are great but I'm trying to identify what might be an issue with my process that's effecting my results.
Everything I've read from Peter Reinheart, Josey Baker, Chad Robertson, Ken Forkish, etc calls for either a short 10-20 min rest, or more commonly a second proofing after shaping loaves, usually until it passes the poke test. When I do this I get a relatively flat loaf with a denser crumb, no big holes or tunnels and not a lot of oven spring. Conversely when I shape my loaves, slash them, and put them straight into the oven I get much better results, more oven spring, more open crumb, taller loaves. What's the story here, why are my results counter to what all the experts are telling me to do?
I'm doing a fairly basic 1-2-3 sourdough, 1 part starter, 2 parts water, 3 parts flour by mass, +0.5-2% of the flour weight in salt depending. My starter is kept room temp at 80% hydration and fed bread flour twice a day at this point (Started with rye transitioned to bread flour over the course of a week when the starter was a month old). I use tap water from the municipal well, the water is slightly hard, but not overly so. For flour it varies but usually either 100% bread flour or 80/20 bread flour & either spelt or rye. Prep the levan first thing in the morning, about 4 hrs later mix the dough in my stand mixer (speed 1 for 2 min, speed 2 for 4-8 min until the dough is smooth, coming away from the bowl, and windowpanes. Proof until doubled, sometimes in the fridge sometimes on the counter. Shape into loaves either batards or boules. Then either rest/second proof, or not followed by baking. Boules get baked in a dutch oven, batards on a baking steel with water added to a hot sheet pan underneath for steam.