Boot on power supply with OnOff SHIM

Hey there,

I use an OnOff SHIM to make sure that my Raspberry Pi stops consuming power when it is shut down. This has the effect that my powerbank, which the Pi is connected to, goes into sleep mode. I cannot avoid this. What I am wondering now is: Is it possible to boot the Pi as soon as I manually activate my powerbank (as it behaves when power supply is connected to the usual usb port)? I know that the whole button functionality is more or less useless when I trigger the booting via the power supply, but still I have the advantage that the Pi does not empty my powerbank once it is shut dwon.