Pitchbend Scaler is a very simple MIDI-only JSFX script that scales incoming Pitchbend messages by a specific factor, each channel has a different factor so it can be customized per-channel. This scaling is useful if the incoming pitchbend range is different than the range expected by the receiving synth after this script, and you can do it per-channel as well. For example a factor of 0.5 on Channel 1 will multiply all pitchbends on that channel by half, which means that the incoming pitchbend range is twice as small as the expected range (let's say incoming pitchbend range is supposed to be ±1 semitone, while the next synth expects ±2 semitones, for example).
Despite the fact that the scale factor sliders are between 0...2, you can actually use any value outside this range, even negative values (which inverts the pitchbend but not as proper as the Pitchbend Inverter); you just have to type them manually instead of moving the slider. (which I recommend anyway for surgical precision to properly compensate for range differences)