This is a quick tip if you are short on screen real estate and what to preview what your external gear is sounding like in one channel.
Using one audio channel and an effects rack you can chain a whole bunch of external hardware effects into one rack and preview all your synths in one channel.

Hope you find the tip useful.

A bit of an update – made this as a preset so you can download and use this with your rig.
Also mapped macros so you can control volumes with your midi knobs.
As seen below. So download the single channel multi-input rack .