As a disclaimer, I do all of my gaming on my PC. But I do do a lot of work to customize input schemes, use multiple adaptive input devices at the same time, make things work with emulators, etc. so I do have some understanding of the sort of issues you would run into trying to do this.
I think the scheme you describe should work, as long as the Cronus can correctly receive software-generated keystrokes from the PC. (Maybe someone's tried? Or else you could ask the manufacturer.) That being said, there are a couple of complexities that you should be aware of. I think they are things that can be solved, but I'd be lying if I said this was going to be simple.
First, how are you getting the video output from the console into the PC? It's not going to be enough to just plug in HDMI cord into the console and a computer monitor; you need access to Windows in order to see the interactors. Probably this means finding some software (and possibly accompanying hardware) to let you view a "stream" coming over HDMI or similar inside of a Windows application. I'm sure this is doable, but I don't know how off the top of my head.
Second, be aware of the limitations of the types of input that Project Iris can provide, as well as limitations that come from needing to actually look at the interactors. As a simple example, imagine that you're controlling your character's movement using the four cardinal directions. The simple approach is to create four interactors and map them to the four arrow keys. You'll need to set these interactors to hold the key down as long as you look at the interactor, as an instantaneous keypress won't make your character go anywhere. But, in order to move, you have to be staring at the interactor. Which means that, for example, you can't see that you're about to walk off a cliff. I have solved this particular problem (and am happy to share), but I suspect you will find many more like it. Control schemes often have far more nuance than it first appears.
Third, each game is probably going to need some custom configuration. Different buttons will be more important and need a more central place on the screen. Some games will require holding buttons while others require tapping them. Joystick emulation will require some fine-tuning. (You're using the discrete input of keypresses generated by interactors to emulate the continuous input of a joystick; it's never going to be perfect, and different games will benefit from different tweaks.) Game selection is going to be important too. Some games just require so many inputs to be handled so quickly; I don't think it's worth fighting with those games. I'd rather play the things I can play well without feeling extra hindered by my disability.
One other tool you might want to look at is Capacita (
https://www.diyability.org/capacita). It's currently still under development, but it is designed to do exactly the sort of task you're talking about.
I hope I'm not scaring you away, because the EyeX and Project Iris are great tools for gaming with a disability. I have been able to significantly expand the set of games I can play by using these tools, and it is awesome! I just want to be honest about what the challenges are, because there definitely are challenges. It's certainly not a ready-made solution, and it doesn't solve everything, but it's a pretty cool solution when you get it working!