Semantics are really important in these situations. We have a system with an E-stop (emergency stop) circuit. Any break in the loop and the system will shut off. It needed to work together with one particular vendors board that insisted on having a "hardware enable" signal that it could control. Rather than adding an additional circuit, someone decided to have "hardware enable" flip a normally open relay in the E-stop circuit. Technically this "works" because enable clears the E-stop condition and allows the thing to function. From a practical point of view this has caused no end of odd problems, particularly when diagnosing issues where things fail because the meaning of this signal has been compromised.

If you're doing three-wire control [0], it also means you can add additional "stop" buttons by wiring them all into the circuit in series.

A nice-to-have addition to your table saw is a big red stop button you can reach with your foot so you don't have to take your hands off of your work pieces to shut the saw down if things have gotten more interesting than you expected them to. Three wire control makes this super easy to add (once you've found the big red mushroom-head n/c switch, of course).

[0] https://twcontrols.com/lessons/control-wiring-3-wire-control...