(Sorry for having to drop off, scheduling conflict.)

To clarify a little and ensure I understand properly:

If my build system has already encoded all of my dependencies in a
secondary layer (my build files), do I care about any of these concerns?

Or, put another way: is the current debate about "I want the build to be
synthesized at compile-invocation time from source, without that secondary
layer"?

I'm reasonably sure from past experience is that a proper modular and
parallized build requires that secondary layer. (To say nothing of
performance concerns: rescanning constantly is a waste of computation.)

Or am I misunderstanding?