[Arbitrum Activates Elara Upgrade, Offering Optional Compliance Filtering and Priority Fee Features for Dedicated Chains] According to The Defiant, Arbitrum activated the ArbOS 61 Elara upgrade on August 20, introducing optional protocol-level transaction filtering, priority fee support, and alternative data availability interfaces for dedicated chains. The upgrade also adjusted base fee management on Arbitrum One and expanded Stylus contract capacity. The compliance filtering feature is disabled by default and requires chain owners to actively configure external compliance service providers (such as TRM Labs or Chainalysis) and set rules, enforced through dual mechanisms of transaction simulation and on-chain guardianship. Similarly, the priority fee feature is disabled by default and must be enabled by chain owners via precompilation. Priority fee collection on Arbitrum One still requires a separate DAO vote.