Aha! Good points indeed.

I just had a first step towards success, thanks to your input! When running
./configure *without* "--prefix=/usr/sox-14.4.2 --disable-shared
--enable-static" arguments, I'm seeing this:

====

ladspa effects.............yes
====

Yes! :D

This also works still:

--enable-static --prefix=/usr/sox-14.4.2

I'll now move on to installing, configuring and testing plugins, keeping
you posted on the next wall or completion of this task. There are still
some uncertainties on how this will work but I'm very close now.

Cheers!

Chris