Uniswap v4 rejected 104,998 ETH calls. PAY would not.
· 6 min read
EIP-5920 proposes a PAY opcode that moves ETH without running the recipient's code. It is Draft, and a pull request proposing it for inclusion merged on August 20. The pitch sounds like a cleaner, cheaper value transfer.
Mainnet has a better explanation. From July 2 through July 13, the Prism contract made 104,998 empty-calldata ETH calls to Uniswap v4's PoolManager. PoolManager rejected every one. Prism caught almost all of those failures and booked 0.813726 ETH as pending credit instead, which is exactly the branch PAY would skip.