Hyperliquid is moving cancel prioritization from the mempool to fully on-chain in a future upgrade. Goal: better liquidity and less toxic flow by making transaction ordering and cancel reliability more predictable. On testnet, the feature is already live on: $kPEPE, $SUI, $INJ, $DOGE, $ARB, $LTC, $OP, $BNB, $AVAX. Non-ALO orders are now held on-chain instead of the mempool, improving cancel reliability for market makers. The implementation is eligible for mainnet-level bug bounties now.