Just to be clear: Sailfish is the firmware for the Motherboard v2.4 (or 2.5 if you happened to recently replace yours). Â The Extruder Controller is a separate board with separate firmware. Â As such, Sailfish itself does not modify the firmware on the Extruder Controller board.Â
Sailfish requires the 3.1 Extruder Controller firmware. Â There has been no later release of the EC firmware.