Send Midi Messages from different Midi Input Devices to different Nodes in the Audio Processor Graph

Is it possible to send midi messages from different Midi Devices to a different subset of the Nodes in the graph that receive Midi? I don't want all the nodes to connect to the midi input from the IO-AudioProcessorGraph thingy itself, but from an input that I can choose...

I tried to work with the MidiInput class but I couldn't find a way to directly send midi to an AudioPluginInstance without using an extra player class. 

Is it intended that this is not possible this way? Or am I simply missing something? 

I think the only way is to create your own sub-class of AudioProcessor which only has a single midi output. This class then streams the midi coming from a device to it's output. You can then attach the output of this AudioProcessor to other Node's in your audio graph. Maybe there is a better way?