The weirdness on automatition for me is setting it up in reverse, say I want CC#24 to control filter cut off in a synth, I couldn't figure that one out yet, I can instead set a hardware control to output CC#24, assign it on the synth with its built in mapping, then set an automatition curve to record the parameter from the synth. A bit weird and neat (I can do changes on the synth interface and get those recorded), but anyway, I can get around that. However, my goal was to set just 1 control to change more than 1 track or synth param (volume for example), but at different ranges. I've set up groups for it, however crossfade can work for only 2 tracks as you said in reverse, which is useful, but falls a bit short if I start adding more tracks for this. With groups at best you get all track volumes to max, or to inf, which doesn't really work.
I should probably have said that earlier, sorry about it. Checked the Ableton site, it seems it could be a solution, though a pricey one. I've recently been exploring MIDI message mapping and morph tools (MIDI effects basically), and only the full suite of Ableton seems to have some additional MIDI effects to do mapping, but I can't pay that price tag. Digging more into those MIDI effects, apparently those are OPT plugins, something called Open Plug-In Technology from Yamaha, something old and almost forgotten. There aren't many devs coding in that, can't find any third party plugins I could try out so far. Only a few threads commenting OPT is not having much support lately.
I could find VST effects that alter MIDI though, but the DAW uses them as audio effects, and inserting one into an audio track kills the audio. So the next thing I've been messing with is routing track to track, since you can set an audio effect as an instrument. I could only chain 1 track. A few threads on other forums suggests the DAW doesn't support MIDI routing from track to track, so I guess that won't be an option.
I feel like I'm entering a rabbit hole now. There are a few other VST effects I can try in the next days. So far my only option is to be able to set up to 2 articulations as different instruments (tracks) and use that grouping. It doesn't feel right to mess with the track's volume though, but I guess that can work to some extent.