I actually use other iMacs as multi displays, in our studio we work on 27" 5k iMacs, I’m the only person that chooses to multiscreen, but we bought 2 of the same models that “werent working properly” for cheap online and use them as displays.
I think they look neater and I’m a OCD when when it comes to using same monitor. size and alignment etc.
If you plug your console into your mac, you can use it as a monitor by using Target Display Mode, Press Command + F2 on the keyboard of the iMac that you want to use as a display.
Loads of people don’t realise you can do it