Finally getting the hang of baking sour dough

I have finally started to understand the baking of sour dough and making some pretty nice loaves. Here is my recipe and technique.
100g starter (fed 12 hours before)
350g filtered water
400g unbleached all purpose flour
100g whole-wheat flour
10g salt
1) mix all the ingredients to shaggy dough stage and cover with damp tea towel for 1 hour.
2) stretch and folds every 30 minutes (4times)
3 cover with a plastic shower cap and leave in a warm place to bulk ferment.
4) once the dough registers 78F it is ready for shaping
5 lightly flour counter and dump dough out gently onto counter
6) shape your dough and let it sit for 30 minutes uncovered
7) tighten the dough by reshaping and put into floured banneton
8) cover with plastic shower cap and place in fridge for 18 hours
9) heat oven to 500F with DO in
10) place dough onto silicone sling and place in freezer for 30 minutes ( my house is warm at the moment and better for scoring)
11) once oven is at 500F take bread out of freezer and lightly flour the top and score with lame
12) take out DO and place bread in the DO and spritz with water, place lid on
13) place a piece of aluminum foil on rack below DO
14) reduce oven to 475F and bake 30 minutes with lid on and then remove lid bake 15 minutes more