Install klipper-virtual-pins

bash
cd ~
git clone https://github.com/pedrolamas/klipper-virtual-pins.git
./klipper-virtual-pins/install.sh

Add virtual pins to printer.cfg

[virtual_pins]

[output_pin fan_factor]
pin: virtual_pin:fan_factor
pwm: True
value: 1.0

[output_pin accel_factor]
pin: virtual_pin:accel_factor
pwm: True
value: 1.0

Configure M106 to use fan_factor

[gcode_macro M106]
rename_existing: M106.1
gcode:
  {% set S = params.S|default(0)|int %}
  {% set P = params.P|default(0)|int %}
  {% set FACTOR = printer['output_pin fan_factor'].value %}
  {% set ADJUSTED_S = (S * FACTOR)|round(0)|int %}
  M106.1 P{P} S{ADJUSTED_S}

Configure SET_VELOCITY_LIMIT to use accel_factor

[gcode_macro SET_VELOCITY_LIMIT]
rename_existing: SET_VELOCITY_LIMIT_ORIG
gcode:
    {% set accel = params.ACCEL|default(None) %}
    {% set accel_to_decel = params.ACCEL_TO_DECEL|default(None) %}
    {% set velocity = params.VELOCITY|default(None) %}
    {% set factor = printer['output_pin accel_factor'].value %}

    {% if accel is not none %}
        {% set adjusted_accel = accel|float * factor %}
    {% else %}
        {% set adjusted_accel = None %}
    {% endif %}

    {% if accel_to_decel is not none %}
        {% set adjusted_accel_to_decel = accel_to_decel|float * factor %}
    {% else %}
        {% set adjusted_accel_to_decel = None %}
    {% endif %}

    SET_VELOCITY_LIMIT_ORIG {% if velocity is not none %}VELOCITY={velocity|float}{% endif %} {% if adjusted_accel is not none %}ACCEL={adjusted_accel|float}{% endif %} {% if adjusted_accel_to_decel is not none %}ACCEL_TO_DECEL={adjusted_accel_to_decel|float}{% endif %}