Can I lazy-load the MM Connect SDK only when the extension is not present?

This is a common optimization, but we don’t recommend it. It forces you to maintain two divergent connection paths in production, and it loses the benefits (6963 discovery, unified events, fallback when the extension is disabled mid-session, connectAndSign, multichain compatibility, etc.).

If bundle size is the goal, lazy-load the SDK on first user interaction — that optimization applies equally to extension and non-extension users without splitting your code paths.