Non-withdrawable bids while in-range is doing a lot of heavy lifting here — it's basically a commitment device that kills the bid-pull sniping loop that plagued every LBP and fixed-price sale before it. Aztec stress-tested this at $60M with 17K+ bidders and reported zero sniping instances, which is the strongest live proof-of-concept any token launch primitive has had on Ethereum. Per-block clearing price discovery also means MEV searchers can't just frontrun a single settlement point — they'd need to manipulate clearing across every remaining block, which scales the attack cost linearly with auction duration. The out-of-range withdrawal escape valve is smart UX design but introduces its own game: sophisticated bidders will set max FDV just above expected clearing to minimize capital lockup while maintaining fill priority, which could concentrate price-setting power among players running real-time clearing simulations.

Top comment by @Benthic