Effect of bulk ferment and final proof times on oven spring

Toast

I've been having some issues with flat loaves. I'm fairly sure it's due to wrong proving times (sometimes over, sometimes under). Pondering some questions/thoughts and was wondering if anyone might know the answers.

If you know you've overproven on the final rise, is there a way to recover things? Like, have you ever tried dumping the dough back together, folding in a bit more flour to feed the yeast, and reshaping into new loaves?

What, if any, effect does the bulk ferment time have on oven spring? Is it possible to overprove in that step?

When your dough totally collapses when you go to score it, is that pretty much always caused by overproving? Or could it also be caused by poor shaping?

If a boule collapsed on scoring and comes out of the oven with little oven spring, shouldn't the crumb be dense? I'm finding that while my loaves have been much flatter lately, the crumb is still quite open. So I'm puzzled as to what exactly is happening (simple physics would suggest that if you haven't changed the recipe quantities, a flatter loaf would result in a tighter/denser crumb).

Does altitude have much to do with oven spring and how big a loaf looks? I've always baked at 5280' and moved to sea level a few months ago, which coincides with when I've noticed my loaves are a lot flatter. I never changed my baking techniques to account for the high elevation, so I'm wondering what, if any, effect being at sea level has upon the finished product.

Thanks in advance for your thoughts.

Yes, you could add more flour, water, and salt and rework the dough as a pate fermentee. Also, regarding overproofing, if you don't degas, the crumb will be bubbly and open although the loaf deflates in a way. Imagine a bubblegum bubble: before peak, it is partway inflated and the skin is tight and strong. after peak, it might have the same amount of air but the walls are saggy and weak. Overproofing has a similar phenomenon.