diff --git a/bin/device-install.sh b/bin/device-install.sh
index 52a848c38..3d20376bc 100755
--- a/bin/device-install.sh
+++ b/bin/device-install.sh
@@ -7,9 +7,9 @@ MCU=""
 # Constants
 RESET_BAUD=1200
 FIRMWARE_OFFSET=0x00
-# Default littlefs* offset.
-OFFSET=0x300000
-# Default OTA Offset
+# Fallback offsets, used only when firmware metadata carries no partition table.
+# These track partition-table.csv; boards with their own table override them below.
+SPIFFS_OFFSET=0x300000
 OTA_OFFSET=0x260000
 
 # Determine the correct esptool command to use
@@ -122,8 +122,15 @@ if [[ -f "$FILENAME" && "$FILENAME" == *.factory.bin ]]; then
         jq . "$METAFILE"
         # Extract relevant fields from metadata
         if [[ $(jq -r '.part' "$METAFILE") != "null" ]]; then
-            OTA_OFFSET=$(jq -r '.part[] | select(.subtype == "ota_1") | .offset' "$METAFILE")
-            SPIFFS_OFFSET=$(jq -r '.part[] | select(.subtype == "spiffs") | .offset' "$METAFILE")
+            META_OTA_OFFSET=$(jq -r '.part[] | select(.subtype == "ota_1") | .offset' "$METAFILE")
+            META_SPIFFS_OFFSET=$(jq -r '.part[] | select(.subtype == "spiffs") | .offset' "$METAFILE")
+            # A partition table may omit either entry; keep the built-in default then.
+            if [[ -n "$META_OTA_OFFSET" && "$META_OTA_OFFSET" != "null" ]]; then
+                OTA_OFFSET="$META_OTA_OFFSET"
+            fi
+            if [[ -n "$META_SPIFFS_OFFSET" && "$META_SPIFFS_OFFSET" != "null" ]]; then
+                SPIFFS_OFFSET="$META_SPIFFS_OFFSET"
+            fi
         fi
         MCU=$(jq -r '.mcu' "$METAFILE")
     else
@@ -154,9 +161,9 @@ if [[ -f "$FILENAME" && "$FILENAME" == *.factory.bin ]]; then
     $ESPTOOL_CMD ${ESPTOOL_ERASE_FLASH}
     $ESPTOOL_CMD ${ESPTOOL_WRITE_FLASH} $FIRMWARE_OFFSET "${FILENAME}"
     echo "Trying to flash ${OTAFILE} at offset ${OTA_OFFSET}"
-    $ESPTOOL_CMD ${ESPTOOL_WRITE_FLASH} $OTA_OFFSET "${OTAFILE}"
-    echo "Trying to flash ${SPIFFSFILE}, at offset ${OFFSET}"
-    $ESPTOOL_CMD ${ESPTOOL_WRITE_FLASH} $OFFSET "${SPIFFSFILE}"
+    $ESPTOOL_CMD ${ESPTOOL_WRITE_FLASH} "$OTA_OFFSET" "${OTAFILE}"
+    echo "Trying to flash ${SPIFFSFILE}, at offset ${SPIFFS_OFFSET}"
+    $ESPTOOL_CMD ${ESPTOOL_WRITE_FLASH} "$SPIFFS_OFFSET" "${SPIFFSFILE}"
 
 else
     show_help
diff --git a/partition-table-t3s3.csv b/partition-table-t3s3.csv
new file mode 100644
index 000000000..603e2fdac
--- /dev/null
+++ b/partition-table-t3s3.csv
@@ -0,0 +1,11 @@
+# Layout for 4MB LILYGO T3-S3 boards (ESP32-S3FH4R2).
+# Reclaims 256KB from spiffs to give the app slot real headroom.
+# flashApp (ota_1) keeps its full 0xA0000 (655,360 B): the unified BLE OTA image
+# (meshtastic/esp32-unified-ota v1.0.1, mt-esp32s3-ota.bin) is 636,544 B, so this
+# slot cannot be shrunk to fund the app slot instead.
+# Name,   Type, SubType, Offset,  Size, Flags
+nvs,      data, nvs,     0x009000, 0x005000,
+otadata,  data, ota,     0x00e000, 0x002000,
+app,      app,  ota_0,   0x010000, 0x290000,
+flashApp, app,  ota_1,   0x2A0000, 0x0A0000,
+spiffs,   data, spiffs,  0x340000, 0x0C0000,
diff --git a/variants/esp32s3/tlora_t3s3_epaper/platformio.ini b/variants/esp32s3/tlora_t3s3_epaper/platformio.ini
index 0830cf303..93cd4d68d 100644
--- a/variants/esp32s3/tlora_t3s3_epaper/platformio.ini
+++ b/variants/esp32s3/tlora_t3s3_epaper/platformio.ini
@@ -13,9 +13,10 @@ custom_meshtastic_has_ink_hud = true
 extends = esp32s3_base
 board = tlora-t3s3-v1
 board_check = true
+board_build.partitions = partition-table-t3s3.csv
 upload_protocol = esptool
 
-build_flags = 
+build_flags =
   ${esp32s3_base.build_flags}
   -D TLORA_T3S3_EPAPER
   -I variants/esp32s3/tlora_t3s3_epaper
@@ -40,6 +41,7 @@ lib_deps =
 extends = esp32s3_base, inkhud
 board = tlora-t3s3-v1
 board_check = true
+board_build.partitions = partition-table-t3s3.csv
 upload_protocol = esptool
 custom_sdkconfig =
   ${esp32s3_base.custom_sdkconfig}
diff --git a/variants/esp32s3/tlora_t3s3_v1/platformio.ini b/variants/esp32s3/tlora_t3s3_v1/platformio.ini
index 95686e417..96103df82 100644
--- a/variants/esp32s3/tlora_t3s3_v1/platformio.ini
+++ b/variants/esp32s3/tlora_t3s3_v1/platformio.ini
@@ -12,9 +12,10 @@ custom_meshtastic_requires_dfu = true
 extends = esp32s3_base
 board = tlora-t3s3-v1
 board_check = true
+board_build.partitions = partition-table-t3s3.csv
 upload_protocol = esptool
 
-build_flags = 
+build_flags =
   ${esp32s3_base.build_flags}
   -D TLORA_T3S3_V1
   -I variants/esp32s3/tlora_t3s3_v1