Switching from Hybrid to CoreXY removes fan settings, even if "Reuse configuration" is selected

[evilC]

What happened

I have the following in my printer.cfg to stop the fan spinning at 100% during boot:

# Set fan to use heater pin (Fix fan spinning at 100% during boot)
# From https://os.ratrig.com/docs/guides/4028/#my-fan-runs-at-100-until-klipper-boots
[fan]
#pin: !fan_part_cooling_pin  # Do not us with toolboard - see https://github.com/Rat-OS/RatOS/issues/157#issuecomment-2425187293
cycle_time: 0.00004
enable_pin: PB11

Whilst trying to debug some layer shift issues, I switched from Hybrid to CoreXY using the configurator
The new printer.cfg completely lacks a [fan] section

What did you expect to happen

It should leave the [fan] section alone when switching

How to reproduce

Enter the setting into printer.cfg, use the configurator to switch from Hybrid to CoreXY

Additional information

Distro: RatOS v2.1.0-RC 2 (bullseye)