Ah I meant seeing the scale in action but no worries.
The button library can do long presses, if you wanted to set it so that short pressing the unit button takes a reading and long press changes the units that would be very easy, just change the SINGLE_PRESS to LONG_PRESS and add the extra if statement. Saves having to cycle the units just to get a new reading.
I don't think it would be much to make it do constant 'live' readings if that's what wanted to achieve here?