The M4 Board which let you add wifi on your Amstrad CPC just got another firmware v2.0.5 beta 10.
It adds the ability to launch hack menu via external button. It requires soldering two wires to the M4 PCB (the wifi module).
If you are happy not using Hack Menu or just launching it from the WEB interface, no reason to make this modification. If you decide to solder on the switch, be aware it is at your OWN risk.
Be careful not to short the wires to the metal housing of the ESP12F module. I recommend to isolate the wires at the resistor and button to avoid an accidental short.