Ok - my take on the cupcake end stop, after trashing the kapton belt for the second time on the automated build platform v1 (ABP). This is due to Z axis skipping so until I can resolve the skipping the importance of a Z stop is critical.

I had a spare microswitch and 10k resistor so came up with this, hope it save's other peoples belts.

P.S. I found it really fiddly to set up but have not needed to adjust once done.

Print out one of ZstopA and one ZstopB

The B print will be a bit lumpy but main thing with it is that it fits inside A, will slide within and does not stick out, a bit of sand paper sorted mine out.

Get your old ethernet cable, cut of one end to the length of cable you need (my cable was actually one I found in my bits box, it actually only had 4 cores to pins 5,6,7 & 8, for this you only need pins 5,6 & 7).

Solder the core that goes to pin 5 of ethernet plug (+5v) to one end of the resister
Solder the core that goes to pin 6 of ethernet plug (Signal) to the other end of the resister but leave long tail. (See picture)
Insulate with tape or heat shrink.
Solder the long tail to common on the switch (use long tail to pull through the eye of the switch lug, you should solder very close to resister and cut of the remaining tail).
Solder the core that goes to pin 7 of the ethernet plug (Ground) to the N/O contact of the switch.
(normally open so that when the switch is pressed it grounds the signal line the 10K ohm resister prevents excessive current from the 5V line).
Cut back all other cores, maker sure no shorts on any cores connected to pins 4 and 8 as these will have +5v and Ground respectively.

Assemble together, although during the above I constantly made sure the lead lenghts were good (hope you do as it was fiddly even then).

Set the set screw so you can adjust switch height both in and out.

Set up your print head to the height you want, move X/Y axis out the way, place switch where you want it with the switch made and mark the holes.

You may need to remove the Z axis plate, I just wound it to the top, drill the holes and fit switch.

MAJOR NOTE MAKE SURE YOU DONT DRILL INTO YOUR ELECTRONICS, notice on my machine the switch is placed between the electronics boards mounting holes.

I did not pre check mine I just plugged it into the Z axis stepper drive top plug and ran the motor with control panel, initially I used my finger to press the switch to make sure it worked then dropped to correct level and adjusted with allen key.