The background is the following: For initialization of a patch, MIDI provides (if implemented) the option to request parameters from a synth. However, in order to properly initialize a patch, it would be necessary to request all parameters and initialize the corresponding controls in MD. Currently, this would require to duplicate all controls in a patch, i.e. add for each control a sibling that serves to request its value.
My suggestion is, to add a new type of control that can sequentially send multiple MIDI/SysEx events. Like this, a single control could be programmed to sequentially send all parameter request commands for a patch, which would in repsonse initiallize all controls of the given panel.
More info in this discussion: http://mididesigner.com/qa/4128/layout-yamaha-tg77-voice-editor?show=5004#c5004