I don’t have an H9000, yet but for your situation, since you’re using Ableton Live, perhaps you can program the changes you want in Ableton. Use it to filter the messages if needed to achive the result you’re after. I have not looked closely at the midi implementation chart for the H9000 but I’m going to (cautiously) assume there is a CC message that can turn the input on/off and control input levels. I’m planning to setup a midi controller to control levels, so I can leave the outputs always on and just control the inputs, maybe for a similar reason like your are thinking. My reason, is I want to use the looping capabilities of the H9000 so my inputs would end up feeding multiple loopers that would be procssed in parallel and then output their own audio outs as well, to be mixed with an analog mixer before going to FOH or monitors etc.. The Softstep would be setup to control the loopers mostly, and maybe I can get a 12 step working as well for setting pitch shifting/harmonization parameters.
I hope my comment is helpful in some way. As I learn more about the capabilites I will for sure come back and post.
