New hotend kit question

So, I ordered the new all metal hotend kit for my TAZ 4. I know it needs a firmware update and my question is, after the update can I still use my original extruder?

I want to modify my original for printing with NinjaFlex and be able to just swap them out but I don’t know if the old one will work after the new firmware.

I am hoping the new firmware just adds support for the fan and higher temps and thus the old one would still work.

Anybody know for sure?

I’m pretty sure you’ll have to reflash the firmware depending which extruder you are using.