TAZ 4 5 differences

If a TAZ 4 is upgraded to use the hexagon hot end and a PEI bed, what are the remaining significant differences between it and a TAZ 5?

The only major differences between the two versions are that the 5 came with an all metal hot end, PEI on the bed, internal wire harnesses to support the extra cooling fans for the all metal hot end, and a different connector for hot ends for ease of use. So once you update for the hexagon hotend and add the PEI there really isn’t any major differences left that came be adjusted. If you flash your firmware as a Taz 5 you will then be working with a Taz 5 for all intents and purposes.

I own a Taz 4 with the original Budaschnozzle 0.35 nozzle (and original wiring harness). The bed however has been upgraded to the new PEI bed. Can I flash it to the Taz 5 firmware, or is there more to it? I know there is a new harness to connect an additional fan… if that’s not a concern, can I flash to the Taz 5 firmware?

If you do not have the all metal hotend with the resistor cartridge the newer firmware will fry the power resistor in the Budaschnozzle as it uses a higher PWM /power setting that the resistor can not conduct to the heat block fast enough and the resistor will over heat and burn up.