Yes, the modifications are to have a "dummy" input port so that you can click on a layout button.
Theoretically, you could make as many dummy ports and fields as you would like.
The layout element is connected to the port with an inputtag and inputmask.
It's primitive, but there's all kinds of interesting things you could do like loading/switching floppies, etc.
Video of it in action (it's super exciting, I know)
The dummy ports aren't connected to the keyboard, but you can activate them with the keyboard using the inputmacro plugin: