is it possible to export the game you’ve made disc and test it on the the console it’s made for without publishing it?
I don’t think you can do any such thing without first publishing the build… sounds like the kind of thing that would come through a hack/workaround of the workflow.
However, that being said, there are ways to live test and approximate the conditions.
For example, if you wanted to test the Xbox 360 input scheme you could get an adapter to let you plug a 360 controller into your PC. If you want to test your development for iPhone or Android, then all you have to do is get the Unity Remote and follow the process to connect your dev to your phone.