diff --git a/CHANGELOG.md b/CHANGELOG.md
index 18fb438..98605fa 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,96 @@ and this project adheres to [Semantic Versioning](https://semver.org/).
 
 ## [Unreleased]
 
+## [1.4.0] - 2026-04-25
+
+### Added
+
+- **RAK4631 WisBlock board support** (nRF52840 + SX1262, RAK19007 base
+  + RAK4631 Core + RAK1921 OLED). The second nRF52840 + SX1262 board
+  alongside the Wio Tracker L1.
+  - `SX126X_POWER_EN` (P1.05) driven HIGH at init — the radio is
+    power-gated on this module; without this the chip has no power
+    and SPI hangs.
+  - HFXO + LFXO external crystals selected in `embassy_nrf::Config`.
+    USB CDC-ACM needs ±500 ppm which the internal RC oscillator
+    can't provide.
+  - `SoftwareVbusDetect(true, true)` so USB enumerates without a
+    `CLOCK_POWER` interrupt handler.
+  - Green LED on P1.03 (RAK19007 Base LED1, active-HIGH) via
+    `SimpleLed`.
+  - Hardware-validated end-to-end: ADVERT round-trip with an external
+    receiver on US915.
+  - Added `debug-checkpoint` blink-map coverage at every TX-phase
+    boundary in `radio.rs`, including a new checkpoint between
+    `prepare_for_cad` and `cad()` so future bring-ups can distinguish
+    a modem-setup hang from a DIO1-wait hang.
+
+- **Adaptive listen-before-talk.** The CAD pre-TX retry loop scales to
+  the active LoRa config instead of running a fixed 10 retries × 10 ms
+  (which was roughly one max-length packet at SF7/BW500 and a no-op at
+  SF12/BW125).
+  - Per-retry sleep is sized to the time-on-air of an assumed-peer
+    80-byte packet under the current SF/BW/CR — cached on
+    `RadioContext`, recomputed on every `SET_CONFIG`.
+  - Retry count = `clamp(floor(BUDGET/T)+1, 1, 10)` with `BUDGET = 2.5
+    s`. Fast configs still get up to 10 retries; SF11/12 degrade to
+    single-CAD-and-bail (logged at config-apply).
+  - Sleeps jittered ±20% per iteration to decorrelate
+    simultaneously-backing-off contenders.
+  - ToA math, CR→{1..4} mapping, retry-count derivation, and jitter
+    helper live in a pure `src/lbt.rs` module — host-testable via
+    `DONGLORA_HOST_TEST=1 cargo test` (13 tests).
+  - Validated on-device: 20 iterations of the AI Bot test flow that
+    previously saw ~2 `ChannelBusy` errors now sees zero at the same
+    SF/BW.
+
+### Fixed
+
+- **First-TX-after-boot reliability on SX1262 boards.** Picked up the
+  upstream `lora-phy` fix that moves the BUSY-handshake check from
+  *after* to *before* each SPI op, per Semtech SX1261/2 §8.3.1, LR1121
+  UM §3, and LR1110 DS §1.2.5. The existing post-op wait is preserved
+  as the belt that closes the BUSY-assertion latency window
+  (T_SW ≤ 600 ns) that a single level-poll can miss. Consumed via
+  `[patch.crates-io]` against `swaits/lora-rs#fix/sx126x-busy-race`
+  until the upstream PR merges.
+  - Hardware-verified on Seeed Wio Tracker L1: 20/20 clean-boot TX
+    (vs ~50% before).
+  - Renames `InterfaceVariant::wait_on_busy` → `wait_until_ready` to
+    match the new semantics.
+- **BUSY pin pull-down → none on nRF SX1262 boards.** SX1262's BUSY
+  pin has an internal 20 kΩ pull-up (datasheet p. 53); our
+  `Input::new(..., Pull::Down)` was contending with it, leaving BUSY
+  at an indeterminate voltage and intermittently mis-reading the
+  chip's ready state. Per `lora-rs/lora-rs#260`, switched to
+  `Pull::None` on both Wio Tracker L1 and RAK4631. The RAK4631
+  appeared to work before, but was affected by the same class of bug
+  per the upstream issue — now deterministically correct rather than
+  "happens to work".
+
+### Changed
+
+- **Build-system DX.** `just flash`, `just flash-probe`, and
+  `just build` accept an optional comma-separated `extra_features`
+  argument that is appended to the board feature, e.g. `just flash
+  wio_tracker_l1 debug-checkpoint`. No more dropping to raw
+  `cargo + rust-objcopy + uf2 cp` for iteration loops.
+- **`just` recipes now resolve all tools through `mise`** via
+  `set shell := ["mise", "exec", "--", "sh", "-c"]`. `cargo`,
+  `espflash`, `rust-objcopy`, `cargo-hex-to-uf2` etc. always pick up
+  the versions pinned in `mise.toml` regardless of `PATH` ordering.
+- **`mise.toml` rust pins now carry ARM targets + clippy**, so a fresh
+  `mise install` is sufficient bootstrapping — no manual
+  `rustup target add` for `thumbv6m-none-eabi` /
+  `thumbv7em-none-eabihf` and no separate clippy install.
+- **New `just flash-dfu` recipe** for the Adafruit nRF52 bootloader
+  (VID:PID `239a:0029`) via `adafruit-nrfutil` under `uvx`, with port
+  autodetect.
+- **Per-board `_info` chain in the justfile** collapsed from a long
+  per-board `if/elif` ladder + per-board `:=` variables into a single
+  `case` statement — one place per board, two lists (names +
+  metadata).
+
 ## [1.3.1] - 2026-04-23
 
 ### Fixed
diff --git a/Cargo.lock b/Cargo.lock
index 26f7900..6ad2de1 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -586,7 +586,7 @@ dependencies = [
 
 [[package]]
 name = "donglora"
-version = "1.3.1"
+version = "1.4.0"
 dependencies = [
  "cfg-if",
  "cortex-m",
diff --git a/Cargo.toml b/Cargo.toml
index 7b7c25a..63a3b71 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -3,7 +3,7 @@ members = ["."]
 
 [package]
 name = "donglora"
-version = "1.3.1"
+version = "1.4.0"
 edition = "2021"
 build = "build.rs"
 authors = ["Stephen Waits <steve@waits.net>"]
diff --git a/TODO.md b/TODO.md
index b4ca18a..aab3a93 100644
--- a/TODO.md
+++ b/TODO.md
@@ -1,82 +1,30 @@
 # Firmware TODO List
 
-## `lora-phy` fix shipped locally; upstream PR pending submission
+## `lora-phy` fix: drop fork pin once PR #428 merges + releases
 
-Branch: [`swaits/lora-rs @ fix/sx126x-busy-race`](https://github.com/swaits/lora-rs/tree/fix/sx126x-busy-race).
-PR not yet opened. Firmware consumes the fix via `[patch.crates-io]`
-pointing at `../../lora-rs/lora-phy`; drop the patch line + pre-release
-selector once upstream releases.
+Upstream PR: [lora-rs/lora-rs#428 — *phy: add pre-command BUSY checks
+per Semtech datasheets*](https://github.com/lora-rs/lora-rs/pull/428)
+(open).
+Fork branch we ship from:
+[`swaits/lora-rs @ fix/sx126x-busy-race`](https://github.com/swaits/lora-rs/tree/fix/sx126x-busy-race).
+
+Firmware consumes the fix via a direct `git` dependency in
+`Cargo.toml`:
+
+```toml
+lora-phy = { git = "https://github.com/swaits/lora-rs.git", branch = "fix/sx126x-busy-race", features = ["defmt-03"] }
+```
+
+When PR #428 merges and a `lora-phy` release ships on crates.io that
+contains it, switch this line back to a normal `lora-phy = "X.Y"`
+crates.io version and drop the explanatory comment block above it.
 
 Hardware-verified on Wio Tracker L1: 20/20 clean-boot TX after the fix
-(vs ~50% before). Adds a pre-command BUSY check before each
-SpiInterface read/write op, keeping the existing post-command wait in
-place. Belt-and-suspenders bracketing: pre-wait per spec, post-wait
-closes the BUSY-assertion latency window (T_SW ≤ 600 ns) that a
-single level-poll can miss.
-
-### PR body
-
-```
-Title: phy: pre-command BUSY check per Semtech datasheets
-
-## Problem
-
-While bringing up a downstream project (donglora), I hit a race where TX commands would occasionally fail. Tracked it down to lora-phy not following the BUSY-handshake algorithm Semtech recommends: the host should wait on BUSY *before* issuing each command, not after.
-
-Details: `SpiInterface::{write, write_with_payload, read,
-read_with_status}` polls BUSY *after* each SPI op.
-
-On fast MCUs (nRF52840 at 64 MHz, release build) this is racy — `embedded-hal-async`'s `wait_for_low` returns immediately if the pin is already low, and the chip takes up to T_SW ns (SX1261/2 §8.3, Fig. 8-3) to assert BUSY after NSS rises. The host polls inside that pre-assertion window, sees a stale LOW, fires the next command while the chip is still busy, and the chip silently drops it. First `lora.tx()` after a clean boot on Seeed Wio Tracker L1 hangs ~50% of the time.
-
-## Authority
-
-- [SX1261/2 datasheet, DS.SX1261-2.W.APP Rev. 1.2](https://cdn.sparkfun.com/assets/6/b/5/1/4/SX1262_datasheet.pdf) §8.3.1
-  "BUSY Control Line": *"it is essential to wait for the BUSY line to
-  go low before sending an SPI command."*
-- [LR1121 User Manual, UM.LR1121.W.APP Rev. 1.2](https://files.waveshare.com/wiki/Core1121/UserManual_LR1121_v1_2.pdf) §3
-  "Host-Controller Interface": *"it is necessary to check the status
-  of BUSY prior to sending a command."* (Applies to the LR11xx family
-  — see also [LR1110 DS Rev. 1.1](https://download.mikroe.com/documents/datasheets/LR1110_datasheet.pdf) §1.2.5.)
-- [RadioLib](https://github.com/jgromes/RadioLib/blob/cffd5af/src/Module.cpp)
-  `Module::SPIwriteStream` / `SPIreadStream` call `waitForBusy()` at
-  the start of every transaction.
-- The [SX1276/77/78/79 datasheet](https://cdn.sparkfun.com/assets/7/7/3/2/2/SX1276_Datasheet.pdf)
-  Table 2 exposes no BUSY pin, so
-  `GenericSx127xInterfaceVariant::wait_on_busy` stays a no-op and the
-  change is behaviorally identical for SX127x.
-
-## Fix
-
-Bracket each `SpiInterface` / `Lr1110SpiInterface` read/write op with
-both a pre- and post-command BUSY wait. The pre-wait is the new
-addition required by the spec; the existing post-wait is preserved as
-the belt that closes the BUSY-assertion latency window.
-
-Why pre-wait alone isn't enough: `embedded-hal-async`'s
-`wait_for_low` returns immediately when the pin is already low. The
-chip takes up to T_SW ns to assert BUSY after NSS rises, so a single
-polling chance — at any side of the SPI op — can see a stale LOW and
-race the next command into a still-busy chip. The repro is
-back-to-back writes inside `sx126x::do_cad` (SetCADParams immediately
-followed by SetCAD): pre-wait alone races, SetCAD is dropped, CADDone
-never fires, `lora.cad()` hangs forever. Keeping the post-wait gives a
-second polling chance after enough time has elapsed for BUSY to be
-reliably observable.
-
-The `is_sleep_command` flag now gates both waits. One callsite flip:
-`sx126x::ensure_ready`'s wake-from-sleep GetStatus pulse passes
-`is_sleep_command=true` so the pre-wait doesn't hang on the
-BUSY-stuck-HIGH chip-asleep state. The next SPI op's pre-wait absorbs
-the wake-completion latency.
-
-No public API signature changes.
-
-## Test
-
-- `cargo clippy -p lora-phy --features defmt-03 -- -D warnings` clean.
-- Hardware: Seeed Wio Tracker L1 (nRF52840 + SX1262), 20 consecutive
-  clean-boot TX cycles → 20/20 (vs ~50% before).
-```
+(vs ~50% before). The fix adds a pre-command BUSY check before each
+`SpiInterface` read/write op, keeping the existing post-command wait
+in place — belt-and-suspenders bracketing that closes the
+BUSY-assertion latency window (T_SW ≤ 600 ns) a single level-poll can
+miss.
 
 ---