I was thinking about the problem of needing to be small for emergency and yet fitting all 4 functions of power in, power out, light, button.
You could make a USB-C variant which merges power and power out. USB-C is becoming common now even not USB-PD they tend to all accept 5V 2A 10W type.
You'd have to be clever with the button, to inform "Powerlight" when it is to active USB-C for output rather than input. On the Powercore USB-C currently it is press a button then plug in to use as output otherwise it acts as input. To do the same with also a button which does lights. Perhaps the button operates the light as normal (always on, strobe, off) and if you pressed it recently it activates USB-C for output, otherwise it uses it for input.