I'm using a novation Launch Control XL and connect it's knobs to a plugin, for example Triple OSC. After generating a nice sound, I have to disconnect every midi knob in order to save my creation as a preset. Because the midi connection will be saved in the preset-file (which is really great), but all knob positions will be set to zero. But even while removing the connection, the value of the knob which been set by the midi-input gets lost.

If there would be a button to erase all midi-connections, and set its last midi-value as it's actual value. I would be able to save one preset as midi-preset, using this for creating sounds via launch control. Then deleting all midi connections while setting its last value to the actual value of the plugin and save it as a real preset.