DIY Curve Tracer 2. - Concept

Now, I'd like to summarize a few design concept for the project.
I started to work from the 3rd version. As I see now, It can be called as the 4th version because it will have so much differences.

1. Modular design. I want to be able to use the design either with internal display or with an oscilloscope
2. Use one 32 bit MCU instead of the current two 8 bit AVR (most probably an STM32)
3. Internal power supply
4. Based on the Huntron Tracker 3200S specification - except the 128bit scanning interface
5. Complettely elliminate mechanical relays (even the reed ones)
6. Get rid of the most of the digital potentiometers - not really fits for the needs, using resistors and analog MOSFET switches instead
7. Get rid of the discrete R-2R DAC using an MCU integrated instead
8. Utilize MCU integrated ADC/DAC/DMA as much as I can
9. Get rid of the trimpots as I can (probably need to keep it for some offset setting functions)
10. Keeping the error of the equipment around 1% every place (it is not a high precision equipment. If we want to decrease the error significantly, it cause significant rise in the costs)
11. Adding the pulse generator as an optional module. It was missing from the 3rd version
12. Adding the lower current limiting resistor ranges (down to 10 ohms)

First of all, I made a block diagram of the equipment: