Is there a way to change the range of pitch bend MIDI events passed to a plugin.
The easiest way to do this is with a MIDI filter. Right click on the plugin slot and choose “MIDI Filters” and setup a controller map filter similar to the following (which would halve the pitch bend range).
To make a change globally rather than just for one plugin, you could use a similar filter on the MIDI Input port in Options → MIDI Ports → double click the port → MIDI Filters.