Hi
Here are some thoughts about a v.2. Make a modular design consisting of RF, processor/digital, display and battery boards. Then each part can be replaced when a better solution is available e.g. replacing the processor/digital board for more power if relevant while keeping the RF board. The display board may not be need by everyone thus reducing cost. I prefer to operate my NanoVNA from the PC due to size and the poor quality of the wheel. Also the battery may not be needed by everyone.
Once you go above ~2 GHz the PCB material becomes a serious issue among other things.
Also name the first port Port 1 and the second port Port 2 instead of Port 0 and Port 1 respectively. This will be more in line with Sxy-port numbering.
Bo
Bo, OZ2M