dense bottom of the loaf.
This is not such an issue with commercial yeasted doughs.
The bottom of my SD boules tends to be denser than the rest of the loaf.
I have observed this across a wide spectrum of hydrations from 65% to 86%. I bake on a thick (3/8") piece of jig plate aluminum that fills the rack. I start at 450 F and turn down adding water when I put the loaves in.
One thing I've tried to eliminate it has been the final rise on heating pad. It sort of works. Maybe I'm not using enough heat.
I used to do an over night ferment with half my flour and all of my wet ( Heavy innoculation) then in the AM I'd add the rest of the flor and salt.
I went through a phase where I was striving for more open crumb and working higher hydrations.
Now I ferment over-night at 86 F with a tiny innoculation of maybe 10% at 68% hydration.
Here is an image https://the-axlotal-tank.smugmug.com/Culinary/i-5c5v5sv/A [1]