Parameters for MIDI Actions

For sending MIDI actions to electronic instruments, like synthesizers, it is desirable to have a variable parameter for each action in the MIDI action dialog. The value of this parameter should be inserted in the corresponding MIDI action by means of a placeholder (e.g. %PARAM% or the like). A typical MIDI action in instruments.xml could then look like

                    <MidiAction name="Modulation Rate">
                          <descr>Set Modulation Rate to given value</descr>
                          <controller ctrl="3" value="%PARAM%"/>
                    </MidiAction>>

The benefit of this would be, to avoid creation of a large number of fixed MIDI actions for each possible parameter value. Currently, this would create a very long list of MIDI actions (see attached example).