I’m trying to reproduce this inside TE:
I add a AuxSendPlugin in my first 8 tracks
auto auxSendPlugin = edit->getPluginCache().createNewPlugin(tracktion::engine::AuxSendPlugin::xmlTypeName, {});
if (auxSendPlugin != nullptr)
{
auxSendPlugin->state.setProperty(tracktion_engine::IDs::busNum, 0, nullptr);
auxSendPlugin->setEnabled(false);
track->pluginList.insertPlugin(std::move(auxSendPlugin), track->pluginList.size(), nullptr);
}
In my 9th track I create this:
Channel 1 should go to channel 3
auto auxReturnPlugin = edit->getPluginCache().createNewPlugin(tracktion::engine::AuxReturnPlugin::xmlTypeName, {});
if (auxReturnPlugin != nullptr)
{
auxReturnPlugin->state.setProperty(tracktion_engine::IDs::busNum, 0, nullptr);
midiReturnTrack->pluginList.insertPlugin(std::move(auxReturnPlugin), 0, nullptr);
}
auto midiPatchbayPlugin = edit->getPluginCache().createNewPlugin(tracktion::engine::MidiPatchBayPlugin::xmlTypeName, {});
if (midiPatchbayPlugin != nullptr)
{
if (auto* patchbay = dynamic_cast<tracktion::engine::MidiPatchBayPlugin*>(midiPatchbayPlugin.get()))
patchbay->makeConnection(1, 3);
midiReturnTrack->pluginList.insertPlugin(std::move(midiPatchbayPlugin), midiReturnTrack->pluginList.size(), nullptr);
}
With this if I open the edit with Waveform I see all correct and If I set output of track 8 to my midi controller i can see the note lighting up the buttons.
The problem appear when I’m trying to set the output to the track:
if (auto* midiReturnTrack = tracks[8])
{
midiReturnTrack->setName("Midi Controller");
auto& trackOutput = midiReturnTrack->getOutput();
auto devices = juce::MidiOutput::getAvailableDevices();
for (const auto& device : devices)
{
if (device.name.containsIgnoreCase("MyController"))
{
trackOutput.setOutputToDeviceID(device.identifier);
trackOutput.updateOutput();
break;
}
}
...
Doing this at the end:
for (int i = 0; i < tracks.size(); ++i)
{
auto* track = tracks[i];
auto& output = track->getOutput();
DBG("[Track " + juce::String(i) + "] name=" + track->getName());
DBG(" output device ID = " + output.getOutputDeviceID());
}
Show:
[Track 8] name=Midi Controller
output device ID = \\?\usb#vid_239a&pid_cafe&mi_00#6&e3c153f&0&0000#{6994ad04-93ef-11d0-a3cc-00a0c9223196}\global
So seams ok but no lights 
For sure when I changed track on my sequencer I do this I enable the auxSendPlugin on the track!
You have any ideas?
Thanks
