you should be able to set their individual controls to the same CC# and use an external midi controller (or your CDM/LE controller in MIDI mode)
Still, it'll be a little clunky, as you wouldn't have individual offset or scaling, just a common controller knob.
Additionally, the midi controller settings, I believe, are global for the plugin, and behave more like the Stand alone preferences, NOT per instance of the plug-in in a stored DAW project, nor stored with a Spark project preset.
good luck.