additional matrixportal buildenv using original adafruit bootloader

you should

first) perform the "bootloader repair" as described in https://learn.adafruit.com/adafruit-matrixportal-s3/factory-reset#factory-reset-and-bootloader-repair-3107941

second) upload partitions.bin and firmware.bin created by the _tinyUF2 build

platformio.ini

@@ -107,6 +107,7 @@ default_envs =
   ;;
   athom_music_esp32_4MB_M
   adafruit_matrixportal_esp32s3 ;;  HUB75 supported
+  ; adafruit_matrixportal_esp32s3_tinyUF2 ;; experimental - uses adafruit bootloader
 
 ; Go to MoonModules environments for environments
 
@@ -2792,9 +2793,9 @@ platform = ${esp32.platformV4_xp} ;; 6.5.0 = first platform release supporting m
 platform_packages = ${esp32.platformV4_packages_xp} ;; arduino-esp32 2.0.14 needed - previous versions were missing files for matrixportal
 board = adafruit_matrixportal_esp32s3
 
-board_build.partitions = ${esp32.large_partitions}
-board_build.f_flash = 80000000L
-board_build.flash_mode = qio
+board_build.partitions = ${esp32.large_partitions}    ;; default 8MB WLED partitions
+;; board_build.f_flash = 80000000L ;; this is the default for board = adafruit_matrixportal_esp32s3
+;; board_build.flash_mode = qio    ;; ditto
 
 build_unflags = ${env:esp32S3_8MB_M.build_unflags}   ;; use the same as "normal" S3 buildenv
   -D ARDUINO_USB_CDC_ON_BOOT=1                       ;; fix warning: "ARDUINO_USB_CDC_ON_BOOT" redefined; comment out for Serial debug
@@ -2823,5 +2824,19 @@ lib_deps = ${esp32s3.lib_deps} ${common_mm.lib_deps_S} ;; ;;  do not include ${e
 lib_ignore = IRremoteESP8266 ; use with WLED_DISABLE_INFRARED for faster compilation
 monitor_filters = esp32_exception_decoder
 ; 
-; RAM:   [==        ]  20.4% (used 66984 bytes from 327680 bytes)
-; Flash: [========= ]  94.8% (used 1491489 bytes from 1572864 bytes)
+; RAM:   [==        ]  18.4% (used 60456 bytes from 327680 bytes)
+; Flash: [========  ]  79.9% (used 1675601 bytes from 2097152 bytes)
+
+;; this buildenv uses the original bootloader and partions from adafruit
+[env:adafruit_matrixportal_esp32s3_tinyUF2]
+extends = env:adafruit_matrixportal_esp32s3
+board_build.partitions = tools/partitions-8MB_spiffs-tinyuf2.csv    ;; use original adafruit 8MB tinyUF2 partitioning
+
+;; we just replace WLED_RELEASE_NAME
+build_unflags = ${env:adafruit_matrixportal_esp32s3.build_unflags}
+  -D WLED_RELEASE_NAME=matrixportal_esp32s3
+build_flags = ${env:adafruit_matrixportal_esp32s3.build_flags}
+  -D WLED_RELEASE_NAME=matrixportal_esp32s3_tinyUF2
+; 
+; RAM:   [==        ]  18.4% (used 60456 bytes from 327680 bytes)
+; Flash: [========  ]  79.9% (used 1675601 bytes from 2097152 bytes)

tools/partitions-8MB_spiffs-tinyuf2.csv

@@ -0,0 +1,10 @@
+# ESP-IDF Partition Table
+# Name,   Type, SubType, Offset,  Size, Flags
+# bootloader.bin,,          0x1000, 32K
+# partition table,,         0x8000, 4K
+nvs,      data, nvs,      0x9000,  20K,
+otadata,  data, ota,      0xe000,  8K,
+ota_0,    app,    ota_0,   0x10000,  2048K,
+ota_1,    app,    ota_1,  0x210000,  2048K,
+uf2,      app,  factory,0x410000,  256K,
+spiffs,   data, spiffs,   0x450000,  3776K,