Linking MacBook Pro and iMac as single system As I’ve moved to working from home during quarantine I’ve found myself in a bit of a situation which I’m hoping you can help me out with. Traditionally I have one workstation (a MBP connected to an external monitor) for video editing, and an iMac for video editing. However I’m hoping to link all 3 of them to make a single workstation like the picture I just took: where I am using the iMac as the base of the system (for its performance) and the MBP and secondary monitor as additional external monitors while being able to use the keyboard and trackpad from the MBP as it’s what I’m most comfortable with.
Is there any way that I might be able to do this?
You could potentially solve this with a product called Barrier and with display sharing software
Note: this is a total bodge and not something I would personally do because you’re likely to spend more time fiddling with it than getting actual work done.
Barrier will let you use your keyboard and mouse on several computers.  Its like a software KVM that works on a client/server model.  All the computers must be on the same network and ideally, you’d use the MacBook keyboard and trackpad to control the iMac.  The external display would be connected to the iMac for simplicity.  To use the MacBook screen, you would need something like Luna Display to extend the display of the iMac to the MBP.
There’s a YouTube video on how Barrier works.  You can also see a demo of Luna Display on Youtube.