This is a great project. A ton of printing but the result is excellent. I have a few comments of interest and a request.
The software works well. The interface is simple. The calibration screen is nicely arranged and functional. When running on an older laptop, it's very responsive.
I tried using a Raspberry PI. I picked up a 3B+ at a local store and started trying to install Windows IOT. It turns out that IOT does not yet support the B+. There's a preview edition that can supposedly be installed but it's documented to have no Wifi support and some other limitations. It amazes me that Microsoft is not yet supporting the 3B+.
I had an older 3B PI running Octopi and decided to set Octopi up on the 3B+ and then I could use the 3B for this. This worked out fine. Octopi runs better than ever (no more delays from camera), and Window IOT installs and works on the 3B perfectly. So, if you want to run this on a PI, find a 3B. Don't bother, for now, with a 3B+.
The software runs well on the 3B. I can sense it's a little slower and less responsive than on the laptop but performance is just fine.
Now we get into the limitations of the software. I really don't like having to use a laptop to run this. With the PI, I can avoid the laptop but still need a keyboard, mouse and monitor. Not a big improvement.
I'm thinking about getting a PI 7" touch display but this is, IMHO, overkill for running the robot. I'd really like it to be headless with some hard buttons for the basic run/stop/off functions.
So ideally, I'd like to see the software enhanced to support the GPIO pins on the PI. I can imagine this would require a new setup screen to tell the software that GPIO pin 20 is Stop, pin 15 is Run etc. Then I could just hook up a few buttons and have a completely independent robot. I am more than willing to hook up a monitor and keyboard for initial setup and calibration. I'd just like to have it fully independent for use without a display and keyboard during normal operation.