There are two types of split keyboard. The first one is one solid body, with divided key segments. The second one are two separated body's, each with their own key-segment. With the second type, the bodies are connected with removable cables, which normally use standard-connections (usb or trrs usually). So they can easily be replaced for longer cables.

Sure did. Just take a look at https://ultimatehackingkeyboard.com/ or similar. There's a cable that separates the two keyboards and they can go further apart than the picture in the article. Or just replace the cable with a longer one.