[ethresear.ch] [Execution Layer Research] PropAMM fills on Ethereum mainnet and PropAMM support for TEMBRI (toolbox): same-block quotes, a small spread, and flow taken from lagging AMMs

▎ Correction (2 November 2026). My post earlier above said " FermiSwap often re-quotes inside a block. " It does not. Each FermiSwap update names one of its eight markets, and the 21% of its update blocks with more than one update are updates to different markets. Over the 30 days, no market on any venue was updated twice in one block, which matches the one update per block that Neuder and Bahrani describe (t/26129). 14% of fills are the second or later fill on the same venue and pair in their block. They trade against the same update: at the first fill’s price at FermiSwap and Tempest, and at a price that depends on size at El Zorro, whose contract adds an impact of 1 bp × fill / vault balance.