Thank you for the reply, @MotleyG
So, I get that I probably shouldn't increase the preamp gain or I may run into clipping issues as you've said DVC is not related, so I'm assuming it's not giving me extra headroom, right?
Also, DVC with BT does actually work with my device and I prefer it enabled. It's actually only some of the older tracks from the 70s and 80s that I'm finding quieter than I prefer. But I think that's probably more an issue of their older mastering than anything else it seems.