Problem solving a recipe made with beer and spent grain

Hello, Bakers! I am brand new to the forum and come to you with what is perhaps too tall of a request.

Background, for those who are curious: I am a homebrewer who loves sourdough and hates food waste. For this reason, after brewing, I dry the spent grains and have been using them to make bread for about 2 years. The spent grains are used as an additive like nuts or seeds, and while they add a nice texture and flavor, I can't use all of the grain left over from brewing without making an insane amount of bread, or filling my freezer with grain waiting to be used, and adding more into it about monthly. For this reason, I decided in January to mill the grain down into flour and try to incorporate that into my sourdough recipe. After many attempts, I am very frustrated with trying to make this work, but I can't claim extensive knowledge of bread baking, so I don't know if I am fixing the wrong things, or if this type of bread is simply impossible.

Actual question: I am trying to combine beer bread, sourdough bread, spent grain, and flour milled from spent grain into a bread. My first attempts came out very very dense with a very fine crumb and no discernable crust.

I have modified the recipe to add more gluten and more water in hopes that the crumb would loose and a crust would form. Now it seems that I don't have enough gluten as the dough shows little holes and pockets when I try to shape it. During the final proof, the bread spread out and formed craggy regions with what I would describe as canyons between. The crumb was much better, and it developed a crust, but the bread remained very flat.

I am using flour that I have milled myself from spent grain used in beer brewing, whole wheat, and all purpose flour. I am starting to think that this combination is simply not possible, although I am not sure why.

Here is the recipe I am using:

• 5.35 oz / 150g active, fed starter (50% whole wheat started, 50% white)
• 15 oz / 425g beer
• 0.9 oz / 25g olive oil
• 3.5 oz / 100g Barley flour
• 7 oz / 200g all purpose flour
• 7 oz / 200g whole wheat flour
• 2 tbsp Vital Wheat Gluten
• 0.35 oz / 10g fine sea salt
• 1.5 C spent grains
• fine ground cornmeal, for dusting

1. Combine the starter, water, olive oil and flours. Squish everything together with your hands until all of the flour is absorbed.
2. Rest (autolyse) for 30 minutes.
3. Add the salt + 1/2 tsp. of water (to help it dissolve). Lift and fold the dough over itself several times, and squish with your hands to incorporate.
4. Bulk fermentation: Cover your bowl with plastic wrap and a clean kitchen towel. Leave it in a warm, sunny spot to rise. Your dough is ready when it no longer looks dense, and has increased in volume about 11/2- 2x its original size. This can take anywhere from 3-12 hours.
5. Stretch & folds: During bulk fermentation, you have the option to perform a series of 'stretch & folds' to strengthen the dough. Simply gather a portion of the dough, stretch it upwards and then fold it over itself. Rotate the bowl 1/4 turn and repeat this process until you have come full circle. Do every 30 minutes for 2 hours.
6. Cut the dough in half to make 2 loaves, or leave it whole for a single loaf.
7. Shape.
8. Second rise: Coat the bottom of your Dutch oven with cornmeal. Place the dough inside for a second shorter rise, about 1-2 hours.
9. Slashing the dough: Right before your bread goes into the oven, make a shallow slash about 2 inches long in the center of the dough.
10. When ready to bake, preheat your oven to 450 F.
11. Place your bread into the oven (lid on) and reduce the temperature to 400 F. Bake for 20 minutes.
12. Remove the lid, and continue to bake (uncovered) for an additional 40 minutes or until deep, golden brown.
13. During the last 10 minutes of baking, crack open the oven door. This allows the moisture to escape, leaving your bread with a crisp crust.
14. Temperature should be 205 F.
15. Cooling: Remove the bread from the oven, and cool on a wire rack for at least an hour before slicing. Don't cut too soon or else the inside will have a gummy texture!

Due to incorporating the whole spent grain, I usually end up kneading those dough 20-30minutes by hand, at which point it usually seems to have a good texture. It is during bulk fermentation and final proofing that it seems to somehow become either too dry (previous versions of the recipe) or lacking gluten.

Has anyone ever tried anything like this? What would you call this flour that I am making?

Am I asking for the impossible here?

All thoughts appreciated, thank you!