diff --git a/.github/workflows/build-solo-firmwares.yml b/.github/workflows/build-solo-firmwares.yml
index e6329011..a6658fbb 100644
--- a/.github/workflows/build-solo-firmwares.yml
+++ b/.github/workflows/build-solo-firmwares.yml
@@ -55,6 +55,12 @@ jobs:
             echo "BUILD_VERSION=dev-$(git rev-parse --short HEAD)" >> $GITHUB_ENV
           fi
 
+      # The L2 links framework libs rebuilt for its own ESP-IDF options
+      # (solo/wio-tracker-l2/idf/sdkconfig), which this env builds first.
+      - name: Rebuild framework libs
+        if: matrix.env == 'Wio_Tracker_L2_companion_solo_lvgl'
+        run: pio run -e Wio_Tracker_L2_idf_libs
+
       - name: Build Firmware
         env:
           FIRMWARE_VERSION: ${{ env.BUILD_VERSION }}
diff --git a/.gitignore b/.gitignore
index 0073cd35..b4c09d0a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -31,3 +31,12 @@ graphify-out/
 
 # local assistant notes
 CLAUDE.md
+
+# pioarduino's framework-lib rebuild (custom_sdkconfig, Wio_Tracker_L2_idf_libs)
+# generates an ESP-IDF project in the repo root
+/.dummy/
+/CMakeLists.txt
+/sdkconfig.defaults
+/sdkconfig.*
+/dependencies.lock
+/managed_components/
diff --git a/README.md b/README.md
index 6d5f4d55..997923ae 100644
--- a/README.md
+++ b/README.md
@@ -62,7 +62,7 @@ pio run -e <env> -t upload                                  # build and flash ov
 FIRMWARE_VERSION=v1.0.0 bash build.sh build-firmware <env>  # release artifacts into out/
 ```
 
-Environments are the `*_solo_dual` (OLED / e-ink) and `*_solo_lvgl` (touch) entries in `solo/<board>/platformio.ini`. Optional hardware (CardKB, joystick, GPIO, buzzer…) is enabled with [build flags](./docs/solo/developer/build-flags.md). Releasing: [RELEASE.md](./RELEASE.md).
+Environments are the `*_solo_dual` (OLED / e-ink) and `*_solo_lvgl` (touch) entries in `solo/<board>/platformio.ini`. The Wio Tracker L2 needs `pio run -e Wio_Tracker_L2_idf_libs` once before its first build (it rebuilds the framework libs for its ESP-IDF options). Optional hardware (CardKB, joystick, GPIO, buzzer…) is enabled with [build flags](./docs/solo/developer/build-flags.md). Releasing: [RELEASE.md](./RELEASE.md).
 
 This README is protected from upstream merges via `.gitattributes`; after cloning run once `git config merge.ours.driver true`.
 
diff --git a/solo/wio-tracker-l2/idf/arduino_tinyusb/CMakeLists.txt b/solo/wio-tracker-l2/idf/arduino_tinyusb/CMakeLists.txt
new file mode 100644
index 00000000..2d2fdb5f
--- /dev/null
+++ b/solo/wio-tracker-l2/idf/arduino_tinyusb/CMakeLists.txt
@@ -0,0 +1,19 @@
+# Stands in for esp32-arduino-lib-builder's arduino_tinyusb during the
+# custom_sdkconfig rebuild: its options (Kconfig), and the framework's own
+# prebuilt library and headers. No sources, so no archive replaces the
+# prebuilt one.
+if(CMAKE_BUILD_EARLY_EXPANSION)   # the requirements scan: nothing to resolve yet
+  idf_component_register()
+  return()
+endif()
+foreach(dir ${EXTRA_COMPONENT_DIRS})
+  if(dir MATCHES "framework-arduinoespressif32$")
+    set(libs "${dir}-libs/${IDF_TARGET}")
+  endif()
+endforeach()
+if(NOT libs)
+  message(FATAL_ERROR "arduino_tinyusb: the Arduino framework isn't among EXTRA_COMPONENT_DIRS")
+endif()
+idf_component_register(INCLUDE_DIRS "${libs}/include/arduino_tinyusb/tinyusb/src"
+                                    "${libs}/include/arduino_tinyusb/include")
+target_link_libraries(${COMPONENT_LIB} INTERFACE "${libs}/lib/libarduino_tinyusb.a")
diff --git a/solo/wio-tracker-l2/idf/arduino_tinyusb/Kconfig b/solo/wio-tracker-l2/idf/arduino_tinyusb/Kconfig
new file mode 100644
index 00000000..d41d7699
--- /dev/null
+++ b/solo/wio-tracker-l2/idf/arduino_tinyusb/Kconfig
@@ -0,0 +1,105 @@
+# The TinyUSB options of the Arduino-ESP32 3.3.12 libs (their values), for
+# the custom_sdkconfig rebuild: the component that declares them lives in
+# esp32-arduino-lib-builder, so without this file they'd drop out of
+# sdkconfig.h and the prebuilt libarduino_tinyusb.a would lose its USB serial.
+menu "Arduino TinyUSB"
+    config TINYUSB_ENABLED
+        bool
+        default y
+    config TINYUSB_CDC_ENABLED
+        bool
+        default y
+    config TINYUSB_DESC_CDC_STRING
+        string
+        default "Espressif CDC Device"
+    config TINYUSB_CDC_RX_BUFSIZE
+        int
+        default 64
+    config TINYUSB_CDC_TX_BUFSIZE
+        int
+        default 64
+    config TINYUSB_CDC_MAX_PORTS
+        int
+        default 2
+    config TINYUSB_MSC_ENABLED
+        bool
+        default y
+    config TINYUSB_DESC_MSC_STRING
+        string
+        default "Espressif MSC Device"
+    config TINYUSB_MSC_BUFSIZE
+        int
+        default 4096
+    config TINYUSB_HID_ENABLED
+        bool
+        default y
+    config TINYUSB_DESC_HID_STRING
+        string
+        default "Espressif HID Device"
+    config TINYUSB_HID_BUFSIZE
+        int
+        default 64
+    config TINYUSB_MIDI_ENABLED
+        bool
+        default y
+    config TINYUSB_DESC_MIDI_STRING
+        string
+        default "Espressif MIDI Device"
+    config TINYUSB_MIDI_RX_BUFSIZE
+        int
+        default 64
+    config TINYUSB_MIDI_TX_BUFSIZE
+        int
+        default 64
+    config TINYUSB_AUDIO_ENABLED
+        bool
+        default y
+    config TINYUSB_DESC_AUDIO_STRING
+        string
+        default "Espressif AUDIO Device"
+    config TINYUSB_VIDEO_ENABLED
+        bool
+        default y
+    config TINYUSB_DESC_VIDEO_STRING
+        string
+        default "Espressif VIDEO Device"
+    config TINYUSB_VIDEO_STREAMING_BUFSIZE
+        int
+        default 64
+    config TINYUSB_VIDEO_STREAMING_IFS
+        int
+        default 1
+    config TINYUSB_DFU_RT_ENABLED
+        bool
+        default y
+    config TINYUSB_DESC_DFU_RT_STRING
+        string
+        default "Espressif DFU_RT Device"
+    config TINYUSB_DFU_ENABLED
+        bool
+        default y
+    config TINYUSB_DESC_DFU_STRING
+        string
+        default "Espressif DFU Device"
+    config TINYUSB_DFU_BUFSIZE
+        int
+        default 4096
+    config TINYUSB_VENDOR_ENABLED
+        bool
+        default y
+    config TINYUSB_DESC_VENDOR_STRING
+        string
+        default "Espressif VENDOR Device"
+    config TINYUSB_VENDOR_RX_BUFSIZE
+        int
+        default 64
+    config TINYUSB_VENDOR_TX_BUFSIZE
+        int
+        default 64
+    config TINYUSB_NCM_ENABLED
+        bool
+        default y
+    config TINYUSB_DEBUG_LEVEL
+        int
+        default 0
+endmenu
diff --git a/solo/wio-tracker-l2/idf/sdkconfig b/solo/wio-tracker-l2/idf/sdkconfig
new file mode 100644
index 00000000..d480cc3d
--- /dev/null
+++ b/solo/wio-tracker-l2/idf/sdkconfig
@@ -0,0 +1,27 @@
+# ESP-IDF options for the L2's LVGL firmware, over the Arduino framework's own
+# (custom_sdkconfig in solo/wio-tracker-l2/platformio.ini; changing this file
+# means rebuilding the framework libs: pio run -e Wio_Tracker_L2_idf_libs).
+
+# The reason for all this: a 32 KB instruction cache (the framework ships
+# 16 KB) and 64-byte data cache lines. LVGL runs from flash and draws into
+# PSRAM; frames draw ~35% faster. Costs 16 KB internal RAM.
+CONFIG_ESP32S3_INSTRUCTION_CACHE_32KB=y
+CONFIG_ESP32S3_DATA_CACHE_LINE_64B=y
+
+# ...won back, and more: TLS (map downloads, live tiles, OTA) and the BLE
+# host keep their buffers in PSRAM.
+CONFIG_MBEDTLS_EXTERNAL_MEM_ALLOC=y
+CONFIG_BT_NIMBLE_MEM_ALLOC_MODE_EXTERNAL=y
+
+# What the framework's own build sets for octal-PSRAM boards, which a rebuild
+# from its generic config would lose: PSRAM up before global constructors
+# (MESH_IN_PSRAM needs it), WiFi TX buffers allocated as needed.
+CONFIG_SPIRAM_BOOT_HW_INIT=y
+CONFIG_SPIRAM_BOOT_INIT=y
+CONFIG_SPIRAM_IGNORE_NOTFOUND=y
+CONFIG_SPIRAM_PRE_CONFIGURE_MEMORY_PROTECTION=y
+# CONFIG_SPIRAM_MEMTEST is not set
+CONFIG_ESP_WIFI_DYNAMIC_TX_BUFFER=y
+CONFIG_ESP_WIFI_DYNAMIC_TX_BUFFER_NUM=32
+CONFIG_ESP_WIFI_RX_BA_WIN=6
+CONFIG_LWIP_TCP_OOSEQ_MAX_PBUFS=4
diff --git a/solo/wio-tracker-l2/platformio.ini b/solo/wio-tracker-l2/platformio.ini
index 15dce0b2..d3088869 100644
--- a/solo/wio-tracker-l2/platformio.ini
+++ b/solo/wio-tracker-l2/platformio.ini
@@ -48,6 +48,9 @@ platform = https://github.com/pioarduino/platform-espressif32/releases/download/
 ; a computer as a USB drive (ui-lvgl/LvglPort.h). A firmware that crashes
 ; early may need BOOT held over reset to flash.
 build_unflags = -DARDUINO_USB_MODE=1
+; Bigger CPU caches and other ESP-IDF options (idf/sdkconfig): the framework
+; libs are rebuilt for them. Build Wio_Tracker_L2_idf_libs first (see there).
+custom_sdkconfig = file://solo/wio-tracker-l2/idf/sdkconfig
 build_flags =
   ${Wio_Tracker_L2.build_flags}
   -D ARDUINO_USB_MODE=0
@@ -121,3 +124,18 @@ lib_deps =
   Preferences
   LittleFS
 
+; Rebuilds the framework libs (ESP-IDF) with the custom_sdkconfig above; the
+; firmware env above then links them. Run once before it, and again after a
+; custom_sdkconfig change (pio run -e Wio_Tracker_L2_idf_libs). Needed because
+; pioarduino's rebuild pass compiles the env's own sources without its include
+; paths and libraries, which fails for ours; this env's only source is the
+; stub sketch pioarduino puts in .dummy/. idf/ supplies the TinyUSB options.
+[env:Wio_Tracker_L2_idf_libs]
+platform = ${env:Wio_Tracker_L2_companion_solo_lvgl.platform}
+board = seeed_wio_tracker_l2
+framework = arduino
+custom_sdkconfig = ${env:Wio_Tracker_L2_companion_solo_lvgl.custom_sdkconfig}
+board_build.cmake_extra_args = -DEXTRA_COMPONENT_DIRS=${platformio.src_dir}/../.dummy;${platformio.packages_dir}/framework-arduinoespressif32;${platformio.src_dir}/../solo/wio-tracker-l2/idf
+lib_deps =
+lib_ldf_mode = off
+build_src_filter = +<../.dummy/*>