Sprouted amaranth

I've made two attempts at making a variation of sourdough bread from Tartine 3 with sprouted amaranth. Formula:

• 350 g whole wheat flour
• 150 g AP flour
• 100 g fed starter
• 10 g salt
• 400 g water
• 125 g sprouted amaranth (drained)

The first loaf came out just ok, a bit dense and flat, but quite edible. I thought the cause of these issues was twofold: 1) the sprouted amaranth might have introduced too much water; 2) I think I rushed the stretch/fold process or the second rise or both - but I was able to shape the dough into a reasonable boule. Not sure.

To improve the next one, I tried reducing the water by 10 grams and taking the proper amount of time (perhaps too much?). The second dough rose and got very nicely bubbly during the bulk rise/stretch fold process. After a couple of hours, I thought it was ready for shaping, but once it was on the board, I could tell that it was not - was tearing- it was late at night, so I put it into the refrigerator overnight. Took out first thing in the morning and did a couple of stretch and folds a half hr apart. It seemed to still be in good "bulk rise condition," but not ready. After some more stretch and folds, it just seemed to disintegrate and lose all gluten development, and seemed wetter - if that's possible. Any ideas? Maybe I misread the original bulk rise and let it go too long before attempting that first shaping. 

How does one recover from this, or is it just not possible? TIA.