5/ The second change follows the same reasoning, but concerns tokens: Today ETH is locked in the `OptimismPortal`. However, to allow these tokens to be transferred across chains without requiring them to be transferred through L1, a shared escrow will be created that will be utilized by multiple projects. This upgrade relocates ETH tokens from the `OptimismPortal` to a separate Lockbox, and a future upgrade will address the creation of the shared escrow.