X-In/1-Out Non-Mixing Extruder Config

@craagle, sorry for the delay, but here is an example that might fit your printer with:

extruder + belted_extruder2
extruder1 + belted_extruder3 + belted_extruder4

[gcode_macro T0]
descripton: extruder motion system and extruder stepper
gcode:
    # Deactivate stepper in my_extruder_stepper
    SYNC_EXTRUDER_MOTION EXTRUDER=belted_extruder2 MOTION_QUEUE=
    SYNC_EXTRUDER_MOTION EXTRUDER=extruder1 MOTION_QUEUE=
    SYNC_EXTRUDER_MOTION EXTRUDER=belted_extruder3 MOTION_QUEUE=
    SYNC_EXTRUDER_MOTION EXTRUDER=belted_extruder4 MOTION_QUEUE=
    # Activate stepper in extruder
    SYNC_EXTRUDER_MOTION EXTRUDER=extruder MOTION_QUEUE=extruder

[gcode_macro T1]
description: extruder motion system and belted_extruder2 extruder_stepper
gcode:
    # Deactivate stepper in my_extruder_stepper
    SYNC_EXTRUDER_MOTION EXTRUDER=extruder MOTION_QUEUE=
    SYNC_EXTRUDER_MOTION EXTRUDER=extruder1 MOTION_QUEUE=
    SYNC_EXTRUDER_MOTION EXTRUDER=belted_extruder3 MOTION_QUEUE=
    SYNC_EXTRUDER_MOTION EXTRUDER=belted_extruder4 MOTION_QUEUE=
    # Activate stepper in my_extruder_stepper
    SYNC_EXTRUDER_MOTION EXTRUDER=belted_extruder2 MOTION_QUEUE=extruder
    
[gcode_macro T2]
description: extruder1 motion system and extruder1 stepper
gcode:
    # Deactivate stepper in my_extruder_stepper
    SYNC_EXTRUDER_MOTION EXTRUDER=extruder MOTION_QUEUE=
    SYNC_EXTRUDER_MOTION EXTRUDER=belted_extruder2 MOTION_QUEUE=
    SYNC_EXTRUDER_MOTION EXTRUDER=belted_extruder3 MOTION_QUEUE=
    SYNC_EXTRUDER_MOTION EXTRUDER=belted_extruder4 MOTION_QUEUE=
    # Activate stepper in my_extruder_stepper
    SYNC_EXTRUDER_MOTION EXTRUDER=extruder1 MOTION_QUEUE=extruder1
    
[gcode_macro T3]
description: extruder1 motion system and belted_extruder3 extruder_stepper
gcode:
    # Deactivate stepper in my_extruder_stepper
    SYNC_EXTRUDER_MOTION EXTRUDER=extruder MOTION_QUEUE=
    SYNC_EXTRUDER_MOTION EXTRUDER=belted_extruder2 MOTION_QUEUE=
    SYNC_EXTRUDER_MOTION EXTRUDER=extruder1 MOTION_QUEUE=
    SYNC_EXTRUDER_MOTION EXTRUDER=belted_extruder4 MOTION_QUEUE=
    # Activate stepper in my_extruder_stepper
    SYNC_EXTRUDER_MOTION EXTRUDER=belted_extruder3 MOTION_QUEUE=extruder1
    
[gcode_macro T4]
description: extruder1 motion system and belted_extruder4 extruder_stepper
gcode:
    # Deactivate stepper in my_extruder_stepper
    SYNC_EXTRUDER_MOTION EXTRUDER=extruder MOTION_QUEUE=
    SYNC_EXTRUDER_MOTION EXTRUDER=belted_extruder2 MOTION_QUEUE=
    SYNC_EXTRUDER_MOTION EXTRUDER=extruder1 MOTION_QUEUE=
    SYNC_EXTRUDER_MOTION EXTRUDER=belted_extruder3 MOTION_QUEUE=
    # Activate stepper in my_extruder_stepper
    SYNC_EXTRUDER_MOTION EXTRUDER=belted_extruder4 MOTION_QUEUE=extruder1

The description field tells you what stepper and motion system are activated with each T# command.

[gcode_macro ACTIVATE_EXTRUDER]
description: Replaces built-in macro for a X-in, 1-out extruder configuration SuperSlicer fix
rename_existing: ACTIVATE_EXTRUDER_BASE
gcode:
    {% if 'EXTRUDER' in params %}
      {% set ext = params.EXTRUDER|default(EXTRUDER) %}
      {% if ext == "extruder" %}
        {action_respond_info("Switching to extruder.")}
        T0
      {% elif ext == "belted_extruder2" %}
        {action_respond_info("Switching to belted_extruder2.")}
        T1
      {% elif ext == "extruder1" %}
        {action_respond_info("Switching to extruder1.")}
        T2
      {% elif ext == "belted_extruder3" %}
        {action_respond_info("Switching to belted_extruder3.")}
        T3
      {% elif ext == "belted_extruder4" %}
        {action_respond_info("Switching to belted_extruder4.")}
        T4
      {% else %}
        {action_respond_info("EXTRUDER value being passed.")}
        ACTIVATE_EXTRUDER_BASE EXTRUDER={ext}
      {% endif %}
    {% endif %}

This is an example ACTIVATE_EXTRUDER macro as well.

If you use, please test and advise of your results.

-JJ