I have found a great new way to add a power button and it has been working flawlessly, but I am not sure how electrically safe it is.
I take a tactile button and connect it between the GLOBAL_EN hole and RUN hole. I press it when I want to boot my RPi4. GLOBAL_EN appears to have a pull-up to 5V and RUN is at 0V when shutdown.
Here is the specific button that I am using (I bought it from Sparkfun):
There are 4 pins, I snap 2 off (both from the same side) and just push the remained 2 pins thru the GLOBAL_EN and RUN board holes (solder not necessary). The pitch of these pins is 5mm (they fit in a breadboard with one space between them). It fits perfectly flush on the board.
Any thoughts on long term damage to the SOC?