In the pattern editor, channel width is set by the "lo/med/hi" buttons.
I'd like to set the width of each channel independently by dragging vertical separators (or by another mean).
The width would snap to the lo/med/hi levels of display.
mockup :
(http://img503.imageshack.us/img503/1804/achanw.gif)
Edit : The dragging area would be limited to the label box (the mouse would turn into 'vspilt' when hovering over separators) to avoid confusion when editing the pattern with the mouse.
As nice as all those requests concerning channel column width are (this is not the only one), I can promise you that they won't be implemented anytime soon. The pattern editor code is pretty bad and such things are currently almost impossible to realize.