This is purely my preference for my preferred subject matter.
I don't expect exceptional amounts of detail in the shadows.
Unless the shadows are an integral part of what I want to portray about my main subject, which is rare, I prefer the shadows fall to black or darn close.
I think this lets the mid-tones and highlights to actually look a bit brighter and more defined, even when printed a bit darker in reality.
This doesn't mean the shadow detail isn't caught on my films though. I shoot normally at recommended norms. For Delta 400 I use EI 500 with my incident meter and DD-X as suggested by Ilford to get normal contrast..
When printing I can typically back off enlarger exposure for these negatives at least 2 stops before shadow details I really want start going away, that's a pretty big safety margin.