Thank you Bhikku, Mog, and Buster for your replies. I'm taking a quick KSMO break this long weekend, but I'll definitely post any future breakthroughs here.

Just before my break, I noticed my normal breaths in between Key Sounds felt very pleasurable if I breathed using my stomach, or breathing into my stomach. At some points, they weren't even "normal" breaths, but deep breaths where I expanded my belly. I noticed extra echo effects doing this. Would this be considered "valley breathing"?

I know Jack has simplified the protocol by just focusing on properly making the key sound and has omitted explanation of valley breathing to avoid complication. Would what I'm experiencing now be considered just naturally doing valley breathing as a consequence of correctly doing the key sound?

Thanks again for your responses!