While not the same as allowing more characters to be viewed at one time, if you hover over the label you can see the full name.
However, given that the instrument itself defines what its automation is called, maybe the ideal workaround would be to include a text field in the automation lane, as is done in the Take lanes. Not only would that let you name the automation lane, you could include notes about its purpose or how it's used. For example, even if you could see the full name of something like "Lowpass Filter Cutoff Frequency" that likely would not be as helpful as a text description of "Lowpass Filter Cutoff Frequency for solo trumpet voice in layered brass sound."
Whaddya think? Worth bringing up with the Bakers?