One of the things I really like in Ableton (and miss in Renoise) is the crossfader on the master channel.
I used to use this a lot to separate parts in the mix. E.G :
Bass, Beats, Percussion, FX assigned to A.
Melodic, Pad, Atmospherics, etc assigned to B.
Then you can quickly ‘jam’ ideas for mixing your track, and then be able to automate the changes.
Taking this a step further, why not have four assignable submixes and an X-Y controller,
allowing you to mix between the 4 sub-groups in real time.
This X-Y controller could work in the same vein as the automator plug-in, where you can drop it on any track and then choose which parameters you want to modulate.
This would be a serious enhancement to Renoise’s Live capabilities IMO.
Jasper
You can make tracks crossfade using midi controller though.
Just bind one controller to two track gains and reverse one. Also you have to set the contstraints.
Taking this step further, you can actually build a X-Y controller like this if you have one physical one.
An extension to this thought…
When you have, say, 12 sliders and 32 knobs on your midi controller, you sometimes forget what a midi controller is assigned to what automation. When you press Cntrl+Shift+M you can see what midi controllers are mapped to which automation curves.
The problem:
Lets say you have 42 midi controlled knobs, or whatnot, each mapped to 2-3 automation curves. This will make a massive list with tiny text and lots of confusion… for me anyway 
The feature I would like :
In the controller mapping view, it would be nice to have a “Find Controlled” feature where if you twiddle a knob or slider, the automated curve (or plug-in’s slider) is scrolled to and highlighted (is there something like this already?). This makes it easy to keep track of what midi controller controls what in your big mess of DSP chains. Basically the opposite of the Cntrl+M screen…
Now, my point. A kewl feature like this would only really make sense if you had a X-Y controller, similar to what jasper suggested, which in effect groups the action of a midi controller : which modules are being used, for what automation curves, and for what limits and with optional inverse per mapping.
So, in effect the X-Y controller becomes a “virtual midi slider” to which you can assign multiple automations, which will have one slider to affect all automations you’ve mapped.
Does this make any sense?
The only initial problem I can think of is how to map automations across tracks and DSP chains… Does it make sense to make it something you can “drop into a track” ? or would it have to be and extension of the controller mapping screen?
Hey Suva…
Just wondering… how do you do that/ Cos my controller requires me to go through lots of button clicking and dealing with a screwy LED display to allow it to control 2 CCs with one fader. I’ve tried doing what you suggest. Binding 1 controller to 2 gains, and it keeps canceling the previous one. I only started using Renoise this weekend, though, so I could def be missing something… 