The MINI E3 V3.0 is an upgraded version of the V2.0. The changes include:

1. New ID design upgrade

2. G0 series MCU- STM32G0B1RET6

3. Heat sink design upgrade, increased heat dissipation area, greatly improved heat dissipation performance

4. Better fan that can control the heat dissipation of the device to lower the temperature of the device5. Increased the thermistor interface protection circuit to prevent burning of the master control chip

You can download firmware from BTT's website here:  (Klipper firmware .)