Who told you Seeed C3 is not supported ? Beside the guys saying it is not powerful enough which is not important if you have few leds ,C3 issue with AR is the bin size so you would have to drop some of the other features for the bin to work , example of a working C3 setup with AR is below :
[env:esp32c3dev_AR]
extends = esp32c3
platform = ${esp32c3.platform}
platform_packages = ${esp32c3.platform_packages}
framework = arduino
board = esp32-c3-devkitm-1
board_build.partitions = ${esp32.default_partitions}
build_flags = ${common.build_flags} ${esp32c3.build_flags} ${esp32.AR_build_flags} -D WLED_RELEASE_NAME=esp32c3dev_AR
-D WLED_WATCHDOG_TIMEOUT=0
-DLOLIN_WIFI_FIX ; seems to work much better with this
-DARDUINO_USB_CDC_ON_BOOT=1 ;; for virtual CDC USB
;-DARDUINO_USB_CDC_ON_BOOT=0 ;; for serial-to-USB chip
-D WLED_DISABLE_ALEXA
-D WLED_DISABLE_MQTT
-D WLED_DISABLE_ADALIGHT
-D WLED_DISABLE_LOXONE
-D WLED_DISABLE_HUESYNC
upload_speed = 460800
build_unflags = ${common.build_unflags}
lib_deps = ${env:esp32c3dev.lib_deps}
${esp32.AR_lib_deps}
