Hello
Re LCD size.
What if e.g. a RPi4 is used as the digital board? I understand that the component cost target is 100 USD. A single RPi is 35 USD so in volume it is probably cheaper. The ADC would have to be on the RF board then, but the RPi would cater for more displays options I think. Another added benefit is the modular design.
For stand alone lab use a display larger than 3,5" would be really nice.
Bo
Bo, OZ2M