FYI my experience with D' version

[Adam D. Ruppe]

I just hit another downside with custom version(): two libraries
might use the same name to mean different things.

The version has no namespacing, so that's another reason for not
using it for custom things. The config modules might be the best 
idea
for libraries too. I wonder if we could do a default module that 
is
easily overridden....