Multiple heater/cartridge for one extruder ? (no replies)

Dear marlin community,

After spending days looking for a solution I'm asking here.
Is it possible to control 2 (or more) cartridges for one extruder ?

I want to use a pellets extruder with 2 (or more) heated zones but with 1 stepper motor. Each heated zone has a different temperature.
Marlin is ready to use mutiples temp_sensors but here how it works

temp_sensor 0 = extruder 1
temp_sensor_1 = extruder 2
temp_sensor_2 = extruder 3

Marlin doesn't allow to use a temp_sensor_2 without 3 extruder declared in configuration.h And for each extruder its wants a motor with “step” and “dir” pins declared…
The only solution I have to try is to create a “fake” extruder and use its temp_sensor for my pellets extruder. I have to declare fake pin for motor “step” “dir”…

Any other solution ?

Thank you for your answer.