I was looking for a way to handle pushbuttons with less inputs
Currently it uses 4 digital pins D2-D5 - one per each button
I made a prototype that returns pushbutton state via SPI with every LCD SPI write that will allow D2-D5 pins to be used for something else.
It will require a simple code modification.
Unfortunately current PCBs I have can't accomodate an additional small SPI controller, but we may implement it in future hardware designs.