I would modify it to have all the normalization on the separate jacks tied to ground so that any unused jacks would act as a ground connection and provide some shielding in the cable. If the jacks being used have a normalization connection that is floating now, it would be pretty easy yo connect them to the ground someway.
-James
Not related to this issue, but will there be a problem because of the use of twisted pairs
Couldn't patching a 'noisy' signal in the same pair as
, say, a 1V/Octave for a VCO, or with an audio signal lead to possible issues .
Also surprised that as an inter-system connector, that it does not provide a common ground connection