External instruments with external plug-in logic pro x

Hi, I know you can route audio from your external instruments through the utility external instrument plug in. I can't seem to find a way of routing the audio the same way when using an external synth editor/controller. For example, when I use my Polybrute I have to route the audio to a separate track when the Polybrute Controller Plug in is loaded into the external instrument slot. The same goes for all of my synths with external editors.

Is there a better way of doing this? Or at least linking the tracks together?

Thanks!

Peter