I know some people do it, so I am also curious to see some examples
Anyone?
If I would do it, I would probably do combination of milling, drilling and VIAs to prepare the debugger board for separation, but I am not sure how easy it would be to break, especially the part with tracks and how it would look after breaking it.
Normally we only place testpoints or I think you can buy a special connector which you can use for this purpose (it has needles/balls to touch testpoints placed in an array)