Create footprint pad with physically disconnected section?

I am struggling to make a footprint where there is a cutout within a larger ground pad where both (discontinuous) pieces of copper are treated as part of the pad:

As soon as I cut off the segment of copper, KiCAD 8 interprets it as not part of pad 17. If I move it back so that it touches it becomes part of the pad again. Is there a way to do this?

(The reason I want this is for teaching purposes. We are making practice soldering boards and would like to have a test point that reaches under each component and allows the student to test if the chip’s ground pad is actually soldered to PCB ground. The idea is that if the part is correctly soldered the test point should be connected to ground through the chip, if it is incorrectly soldered it will be floating.)

Just build the pad with a bunch of rectangles, all with the same pad number

Building a pad which consists of two separated areas: place two pads with the same padnumber.

But: For your usecase this will not work. Later in the pcb-design process kicad will connect both same numbered pads (with ratsnest lines) - this will counter your usage (separate tracks on the big GND pad and on the sense-GND pad).

To satisfy Kicad and the requirements for nets/pads/numbering you have to draw a separate sense-pad with a separate sense-pad number. Additionally you also have to draw a separate symbol, which must include a additional sense-pin (with sense-pin number == sense pad number).
On this added “sense” pin you may connect the testpoints to measure the sense pin.