[LAU] Fluidsynth map channels to audio outputs?

So, in Fluidsynth setting synth.output-channels to a number greater than 2 will create pairs of L + R channels. Now, is there a way to map MIDI channels to audio output channels. E.g. MIDI 1 -> audio 1 & 2 The obvious advantage is the possibility for example to record into ardour on separate tracks without having to manually play over and over muting midi tracks etc. From what I understand from the manual the router is only applied to MIDI. Qsynth actually does seem to have exactly this option in Setup > Audio there is a checkbox "Multiple JACK Outputs" and the tip says "Create Multiple JACK output ports for channels, groups and effects". But selecting it has no effect, and actually overrides and ignores the Audio Channel setting. Any help appreciated. Lorenzo