If your manual refers to a "hot" firmware (meaning recently released or high-performance), note that the EUP 081802 uses a proprietary bootloader via the RS-485 port. To update:

The MB DIG43L offers a cabin that’s both luxurious and practical, tailored for every journey.

The original design assumed forced air cooling (a 40mm fan at 15 CFM). In retrofit applications, the fan is often omitted.