A VST MIDI Effect is a VST Plugin that can process MIDI messages. You can select a VST MIDI Effect by clicking the MIDI effect slot's down arrow. The VST MIDI Effect plugins appear in the list's Plugins section.
Note: the 'Apply to track' option relies on plugins being able to save and restore settings, so it won't work with demo versions that can't do this.
VST2 MIDI effects do not receive per-note controls. MIDI output from VST2 plugins is converted from MPE to MIDI 2.0. You can avoid this by setting the per-note pitchbend range to zero (in this case MPE to MIDI 2.0 conversion will only take place if the plugin sends MPE configuration messages (RPN 6)).