How Does a “Last Look” Mechanism Relate to the Concept of Quote Firmness?

A "last look" mechanism allows the Liquidity Provider (LP) a final opportunity to accept or reject a trade after the client has hit their quote. It essentially makes the quote non-firm, as the LP can withdraw it, often citing stale pricing or an inability to hedge.

This is controversial as it protects the LP at the expense of the client's execution certainty.