Electrum ABC 5.4.2

• Enable downgrading of Trezor firmware (D17482).
• Increase the timeout for entering bootloader mode when installing
  custom firmware on a Trezor device, as the previous duration can be
  insufficient depending on USB connection speed (D17843).
• Handle a potential LibUSB error during session closure when
  transitioning to bootloader mode. This error does not impact the
  firmware installation process, so it no longer prevents firmware
  installation (D17844).
• Fix an error that occurs when opening the Trezor Settings dialog
  while the device is locked (D17845).
• Add eCash native support to Trezor One (D17770).

Electrum ABC 5.4.1

• Make it possible to sign Avalanche stakes using Trezor devices running a custom firmware (D17573, D17787).
• Add tools to the Trezor Settings menu allowing to update the firmware of Trezor devices or install a custom firmware from a file (D17798).
• Add a tool to install an eCash firmware capable of signing Avalanche stakes on the following Trezor devices: Trezor T, Trezor Safe 3, Trezor Safe 5 (D17799).
• Detect ALP tokens and prevent their accidental burning when sending XEC, using Cash Fusion or consolidating coins (D17770, D17777, D17806, D17808).
• Make it possible to spend manually selected coins with SLP or ALP tokens attached. The tokens are burned when doing that (D17809).
• Fix a bug that caused the Max button to become untoggled when starting to edit the Pay-to field if it is initially empty (D17651).
• Fix an issue with newer versions of the protobuf library when running CashFusion (D17670).

Electrum ABC 5.4.0

• Remove explorer.bitcoinabc.org from the list of available block
  explorers (D16875).
• Improve compliance with the JSONRPC 2.0 spec (D17185).
• Implement autocompletion when recovering wallets from mnemonic seed
  phrases. This makes wallet restoration faster and less error-prone.
  (D17569).
• Make the derivation path scanner support passphrase protected BIP-39
  and SLI-P39 mnemonics (D17576).
• Trezor related features and bugfixes:
  • Support Trezor Safe 5 hardware wallets (D17294).
  • Add native support for Trezor devices. New wallets created with the
    latest firmware installed on the device will now use the 899'
    derivation path, show amounts in XEC units and display ecash:
    addresses (D17129).
  • Support initializing or recovering a Trezor device with a SLIP-39
    seed phrase (D17555).
  • Support software recovery of SLIP-39 (Shamir Backup) wallets (D17577).
  • Support Trezor's seedless mode for redundant multisig setups when
    initializing a device (D17553).
  • Support Trezor One devices that are locked with a PIN longer than 9
    digits (D17561).
  • Fix a race that prevented the "Check your Trezor" popup to be properly
    closed after validating a passphrase on the device (D17547, D17563).
  • Fix the home screen image customization for all Trezor devices
    (D17546, D17554).
  • Fix resetting of the home screen image (D17578).
  • Provide 1-click way to set the eCash logo as the home screen image
    (D17579).

Electrum ABC 5.3.0

• Fix the fiat price cache file not being created when a fiat currency is selected for the first time (D16663).
• Use libsecp256k1 for elliptic curve point addition (D16684).
• Make libsecp256k1 a mandatory dependency, remove the slow pure-python fallback code (D16689, D16690, D16705).
• Update protobuf files to make it possible to run Electrum ABC from sources with a newer protobuf version than the one specified in the requirements (D16702).

ElectrumABC 5.2.14

• Fix a potential OOM crash when opening a BIP72 URI pointing to a very large file. Electrum ABC will stop downloading the payment request if it exceeds a maximum size of 50kB (D16415).
• Support the latest version 0.13.9 of the trezor library (D16406).
• Fix decoding of transaction inputs with non-multisig p2sh scriptsigs (D16391).

ElectrumABC 5.2.13

• Fix support for recent versions (>= 2.4.1) of the Ledger apps.
• Fix an error on Windows when the application is started while it is already running in another process.

Electrum ABC 5.2.12

• Disable "Generate Key" button in the Delegation editor for non-HD and watch-only wallets (D15013).
• Improve the error message when the user cancels the password dialog in the proof editor (D15040).
• Support Trezor Safe 3 hardware wallets (D5197).
• Drop support for the bitcoincash: cash-address prefix and fix support for the ectest: prefix in testnet mode (D15245).
• Drop support for python 3.8 (D15373).
• Support parsing multi-output payment URIs (D15250).
• Add a warning dialog when a large amount is entered in the Send tab via a payment URIs, to prevent users from being one accidental click away from sending eCash after clicking on a malicious URL (D15396).
• Improve detection of the delegator key when building an Avalanche Delegation from an Avalanche Proof (D15708).
• Fix clearing of the wallet password when Avalanche widgets are closed if the cached password is shared with a parent widget (D15700).
• Fix fetching and caching of historical fiat exchange rates (D15841).
• Add an option to always save new addresses when using the "Scan More Addresses" tool, even if no transaction history is found for any scanned address (D15849).

Electron Cash backports:

• Validate hosts and ports in the Network dialog widgets (D15195).
• Bump docker version to Ubuntu 20.04 for AppImage building (D15522).
• Bump python version to 3.11.8 for binary releases (D15527).

Electrum ABC 5.2.11

• Show a single popup dialog with a progress bar when broadcasting multiple
  transactions instead of showing one popup per transaction (D14853, D14854).
• Fix a bug causing the local chain of headers to get stuck and new
  transactions not showing as verified in the GUI after a single block reorg
  (D14968, D14944).
• Fix an error when the user cancelled the password dialog when using the
  Generate Key button in the Avalanche delegation editor (D14842).
• Bump the checkpoint to a more recent block (D14972).

Electrum ABC 5.2.10

• Don't change the master private key every time the Avalanche proof editor is opened. This improves the automatic key detection when loading an Avalanche proof by making it less likely that the proof's key is beyond the gap limit for key detection (D14804).
• Fix automatic private key detection when building multi-level Avalanche delegations in a wallet that owns the key for the previous level (D14802).
• Fix an integer overflow when displaying the total amount of stakes in an Avalanche proof (D14781).
• Fix transaction signing in CashFusion, broken in 5.2.8 and 5.2.9 (D14795, D14810).
• Fix miscellaneous bugs and improve test coverage for RPC commands (D14780).
• Electron Cash backports:
  • Speed up loading of very large wallets and misc performance improvements (D14703, D14785)

Electrum ABC 5.2.9

• Implement the option to remove coins from the list of stakes in the proof
  editor (D14761).
• Fix the automatic detection of the master private key when loading a proof
  created by the same wallet (D14726).
• Fix the decryption of encrypted hardware wallets, broken in 5.2.8 (D14645).
• Suppress a RuntimeError when the release checker fails to start a new thread
  (D14674).