One other idea...
If the point here is to have something that works with Ableton, this sounds like a capital reason to build a build that's actually a VST controller. No voicing, just various modulation and CV generation modules which use the ES-9 as the "front door" to CV Tools, from which you can use the various Suite widgets and voodoo to pipe the incoming signals to VSTis and VSTs. This will 100% result in something which can make those plugins do things that...well, they're not exactly meant to do. That way, you get the ease of having your voicing under Ableton, but the trickery that makes the voicing do all the odd flips and leaps is very hands-on, as wanted.
And of course, you can save the voicing and Ableton routings, while letting the analog end of this be the "wild card" instrument. Has potential, I think...