@gerb45 I did a little bit of testing with Raspberry Pi OS on a Pi Zero 2w and a PowerBlock. This should work for a RPi4. You can add the following to config.txt to emulate the driver. (This way you don't have to worry about startup scripts.)

dtoverlay=gpio-poweroff,gpiopin=17,active_low=1,inactive_delay_ms=0 dtoverlay=gpio-shutdown,gpio_pin=18,active_low=0,gpio_pull=down

It seems to work identical, except that it indicates boot finished before boot actually finished. (Can anyone confirm this please?)