SKR 2 extruder issues

When I create a printer.cfg with only E0 listed with its values, I get an error that I need to specify micro steps for E1, even if it is not in the fhe file anywhere. If I add it is, I have to set min temp to -100 as there is nothing connected, but then I get an error when heating because its trying to heat both hotends. Please can someone assist with this issue? Below is my cfg file.

# This file contains common pin mappings for the BigTreeTech SKR 2.

# To use this config, the firmware should be compiled for the

# STM32F407 with a "32KiB bootloader".

# The "make flash" command does not work on the SKR 2. Instead,

# after running "make", copy the generated "out/klipper.bin" file to a

# file named "firmware.bin" on an SD card and then restart the SKR 2

# with that SD card.

# See docs/Config_Reference.md for a description of parameters.

# Note: The initial revision of this board has a flaw that can cause

# damage to itself and other boards. Be sure to verify the board is

# not impacted by this flaw before using it.

[virtual_sdcard]

path: ~/gcode_files

[pause_resume]

[display_status]

[gcode_macro CANCEL_PRINT]

description: Cancel the actual running print

rename_existing: CANCEL_PRINT_BASE

gcode:

  TURN_OFF_HEATERS

  CANCEL_PRINT_BASE

[stepper_x]

step_pin: PE2

dir_pin: !PE1

enable_pin: !PE3

microsteps: 16

rotation_distance: 40

endstop_pin: ^PC1

position_endstop: 0

position_max: 300

homing_speed: 50

[stepper_y]

step_pin: PD5

dir_pin: !PD4

enable_pin: !PD6

microsteps: 16

rotation_distance: 40

endstop_pin: ^PC3

position_endstop: 0

position_max: 300

homing_speed: 50

[stepper_z]

step_pin: PA15

dir_pin: PA8

enable_pin: !PD1

microsteps: 16

rotation_distance: 8

endstop_pin: ^PC0

position_endstop: 0.0

position_max: 400

[extruder]

step_pin: PD15

dir_pin: !PD14

enable_pin: !PC7

microsteps: 16

rotation_distance: 34.406

nozzle_diameter: 0.600

filament_diameter: 1.750

heater_pin: PB3

sensor_type: EPCOS 100K B57560G104F

sensor_pin: PA2

control: pid

pid_kp = 28.224

pid_ki = 1.742

pid_kd = 114.306

min_temp: 0

max_temp: 250

pressure_advance: 0.0999

#[extruder1]

#step_pin: PD11

#dir_pin: PD10

#enable_pin: !PD13

#microsteps: 16

#rotation_distance: 34.406

#nozzle_diameter: 0.600

#filament_diameter: 1.750

#heater_pin: PB4

#sensor_type: EPCOS 100K B57560G104F

#sensor_pin: PA3

#control: pid

#pid_kp = 28.224

#pid_ki = 1.742

#pid_kd = 114.306

#min_temp: -100

#max_temp: 250

#pressure_advance: 0.0999

[heater_bed]

heater_pin: PD7

sensor_type: NTC 100K beta 3950

sensor_pin: PA1

control: pid

pid_Kp: 58.035

pid_Ki: 0.557

pid_Kd: 1512.549

min_temp: 0

max_temp: 130

[fan]

pin: PB7

[heater_fan fan1]

pin: PB6

[heater_fan fan2]

pin: PB5

[output_pin motor_power]

pin: PC13

value: 1

[mcu]

serial: /dev/serial/by-id/usb-Klipper_stm32f407xx_210049001650325237333520-if00

[printer]

kinematics: cartesian

max_velocity: 300

max_accel: 500

max_z_velocity: 10

max_z_accel: 500

########################################

# EXP1 / EXP2 (display) pins

########################################

[board_pins]

aliases:

    # EXP1 header

    EXP1_1=PC5, EXP1_3=PB1, EXP1_5=PE10, EXP1_7=PE12, EXP1_9=<GND>,

    EXP1_2=PB0, EXP1_4=PE9, EXP1_6=PE11, EXP1_8=PE13, EXP1_10=<5V>,

    # EXP2 header

    EXP2_1=PA6, EXP2_3=PE7, EXP2_5=PB2, EXP2_7=PC4,   EXP2_9=<GND>,

    EXP2_2=PA5, EXP2_4=PA4, EXP2_6=PA7, EXP2_8=<RST>, EXP2_10=<NC>

# See the sample-lcd.cfg file for definitions of common LCD displays.

########################################

# TMC2209 configuration

########################################

[tmc2209 stepper_x]

uart_pin: PE0

run_current: 0.580

hold_current: 0.580

diag_pin:

[tmc2209 stepper_y]

uart_pin: PD3

run_current: 0.650

hold_current: 0.650

diag_pin:

[tmc2209 stepper_z]

uart_pin: PD0

run_current: 0.580

hold_current: 0.580

diag_pin:

[tmc2209 extruder]

uart_pin: PC6

run_current: 0.650

diag_pin:

[tmc2209 extruder1]

uart_pin: PD12

run_current: 0.600

diag_pin:

When I save and run like that I get the following:
Option ‘microsteps’ in section ‘extruder1’ must be specified

Edit Sineos: Use Code Tags

With the commented [extruder1] section you get the error?
Maybe because you have an active [tmc2209 extruder1] section an so Klipper expects to have a fully configured driver.