Ok you have peaked my interest. If I was doing the router table and wanting to get into CNC at some point in the future I would build the table this way
1.
https://www.ebay.com/itm/30309613370...kAAOSw~llcThjl This should be a ebay listing for a CNC Z axis mount. I would drill and tap the end opposite the NEMA 23 motor mount and mount this end onto a 3/8" aluminum router plate to set in the table top. You will need to have built a aluminum mount for your router motor.
2. If you can program an arduino then use
https://www.amazon.com/STEPPERONLINE...s%2C315&sr=8-3 from amazon to control the up and down function with a NEMA 23 stepper motor.
3. For control, height setting and displaying the height a
https://www.amazon.com/Nextion-Enhan...%2C295&sr=8-27 display.
Putting this all together will teach you a lot about CNC machines and programming will not be so difficult since there are many examples of using an arduino with stepper motors.
With this setup you will have an equal system like the one in Houston with a lot more Flexibility using the Nextion touchscreen display. Also you will need a 24Volt switching power supply for the stepper and a buck converted to drop the voltage for the arduino. Use an arduino Mega 2560 which will give you the best options for setting up auto zero etc. BEWARE - when using a touch Zero to set a zero point you must program de-bounce into the software for accuracy
I would only use switches for limiting the movement of the Z - you can de-bounce these in software and you won't have to worry about all of the nuances of some of the electronic proximity switches.