Ethereum → existing protocol + millions of accounts → years of coordinated migration. QMS → post-quantum finality from genesis + signature-free block production → fewer layers to retrofit later. As Ethereum’s post-quantum work shows, the challenge goes beyond replacing cryptography. Wallets, bridges and infrastructure must migrate too. The key distinction is that QMS designs its consensus and finality layers for post-quantum security from the start, while retaining Ethereum-compatible signatures at the execution layer. Building for a future threat is easier than rebuilding around it after adoption. #QMS1002