My rig is much more complicated...
Input 1 is instrument input from Shure GLXD.
Input 3 is IEM mix from X32 (stereo).
Input 4 is 4CM amp send, set in amp part of patch.
Output 1 (after cab blocks) is used for IEM, it is connected to PSM300. I did it that way to have possibility to use backing tracks from USB or X32, I can work with IEM or headphones connected to from of III.
Output 2 (after cab block) is going to FOH, or in my case to splitter in X32 rack that goes to FOH and to X32.
Output 3 is 4CM amp return, that is my PA. Out block is set before cab blocks in patch.
Output 4 is 4CM amp in, it is inside patch prior to input 4.
I have also switch and potentiometer connected to pedal inputs of III, that switching on and off patch signal to out 1 (I can have IEM mix just from X32 or additionally mixed with patch signal) and regulating signal to IEM level (pot at 50% is 100% of both).
All patches I use have the "IEM module" (for routing IEM), all of them works without amp, so my GK amp is an option.
All that gives me lot of flexibility for playing (IEM, headphones, PA), and modularity - amp is in separate rack. Maybe there is few more cables inside the rack, but actually I am finding pleasure in building racks, I have also built 16U IEM/studio rack form my band.
The II form the picture taken at home is actually in use by my band fellow, it is on top of X32 rack.