Just made another batch today. Quick Q but what does it typically mean if my loaf is lacking in flavor? After initially mixing and letting sit for 30 minutes, I did 4 folds 30 mins apart across 2 hours before sticking it in the fridge overnight for about 8-9 hours to bulk ferment. Did I not allow it to bulk ferment for long enough? I'm still not sure how to go about bulk fermentation, logistically, when I don't want to leave it out but want to slow it down enough in the case of when I am splitting this between days because I don't want to stay up all night. Is it OK to remove the dough from the fridge during bulk fermentation in hopes of expediting the process of fermentation? And if so, how much longer do I let it rest at room temp? I know they say it varies by environment but I also find it odd that there are still general time ranges given (like 4-6 hours at room temp and as long as 8-24 hours in the fridge lol).
Did I not use enough starter? I had about 160-170grams of starter to 800g~ of flour.
The loafs came out fairly decent but still lacking in height:


Something I can help with! Small book incoming, as there are a lot of variables I don't know and want to address.
Are you intending this sourdough to be 10% starter? Because, while 160-170gms of starter is 20% of the flour weight, starter is measured by what weight of the flour is in the starter. So if you're looking for a total of 800 grams of flour, for 20% in the starter, you'd have 640g of dry flour and 320g of starter (assuming your starter is equal parts flour and water). 640 + (320/2) = 800g flour total in your recipe. Lower amounts of starter are perfectly reasonable, if you are willing to let them sit for longer. That could be part of the issue, that it did not bulk ferment long enough with that amount of starter. Generally, lower starter amounts will lend to a greater sour flavor (seems counterintuitive, I know).
How active is your starter? Is there liquid sitting on top when you use it? If so, it is hungry and needs better feeding before using it as your sole leavener in a loaf. I save my discard for all kinds of things that I will leaven by other means (or that don't require leavening), but for sourdough loaves your starter needs to be strong and active.
I see that you did several stretch and folds, but did you perform a windowpane test before moving to bulk ferment? It's important that your gluten development is solid in order to see the maximum rise. If you do your stretch and folds but don't get a good windowpane (light visible through thinly stretched dough without the dough tearing), it's okay to wait another 30 mins and stretch and fold again until you do get a windowpane.
I almost always will bulk ferment at room temp (generally for 3-5 hours with 20% starter), then shape and retard the loaf (put it in the fridge overnight). I have had success with overnight fridge bulk fermentation, then letting it sit out for about an hour, then shaping and returning to the fridge for 2-3 hours before baking. The dough will tell you when it's ready to be shaped. If you poke it gently and it springs back some, but not completely, bulk fermentation is done. It can be really hard at first to figure it out, and I had a lot of short dense loaves before I had even one good one.
Additional flavor component is salt; what is your salt percentage? I go with 1.5-2% which seems to be the general recommendation. Less is a little flaccid; more can be overwhelming. But the right amount of salt will make the loaf sing.
And lastly, at least for now, letting your loaf sit even after baking deepens the sour flavor if left at room temp. When it takes me a few days to get through a loaf, the sourness comes out more later on. And I don't see much deterioration in the softness/moisture of the bread over that length of time.
Hopefully some of that is helpful to you!