Bachus, my point was that there are some arrangers that already are capable to edit synth tones in real time.

Actually , the sliders on the G70/E80 have an advantage over limitess knobs...not only do they "not" remember the settings when you change a tone (just like knobs), you have to move to the factory setting before they are active (No surprises)..the advantage is you can see the exsisting settings on the screen, before you edit,and they will show the results on the screen too.

No it is not a complete editing tool, but it also does a lot more than any controller (arranger)..
There are also midi control apps for android, I use Midi Commander..