Tartine 70% WW x 4

Howdy!  First time trying the Tartine 70% whole wheat loaves.  Refreshed my starter Friday night, made the leaven Saturday morning. Saturday afternoon I decided why not use all the leaven and double the recipe?  So I used 1400g ww and 600g ap, 1600g 75F water, 400g leaven, 40g salt.  I gave it a 1 hr autolyse, then added salt and 25g more water.  Dough was already feeling fairly together, as though it had already undergone several stretch and folds.  I took it through 5 S&Fs over a few hours, keeping the dough between 76F and 72F, then retarded for 12 hrs unshaped.  In the morning I divided the dough into quarters, then because the dough was so stiff I shaped it with turn and drags instead of folding it in thirds and then turn and drags.  The skin was pretty taut, and I let the boules rest on my board for 20 minutes before placing them in bowls and a banneton.  They hardly spread at all.  I placed two back in the refrigerator and took them out an hour and two hours later.  Loaf 1 I proofed in the oven with the light on to speed up proofing - it took 3 hours. Loaf 2 I left at room temperature 68F for 4 hours, and Loaves 3&4 at room temp for 4.

When I scored the loaves they seemed perfectly proofed - nice clean cuts with no outrageous oven springs.  I baked at 475 for 20 then 475 with no lid for 20 or 25 more. They registered around 210F - I was reluctant to keep taking them in and out and my thermometer takes 30 seconds each time, but maybe I should've baked a bit longer. Loaf 1 is pictured above and is a bit moist in the center but nicely baked everywhere else.  Loaves 2 & 3 I'm giving away uncut. Hoping Loaf 4 looks as good inside.