We use this to register our preload purely for performance reasons. In this and many other cases CommonJS is still faster than ESM. Using --require is about 0.5ms overhead vs 4.6ms for --import (on my M1 Macbook Pro).

Relatedly Node.js recently (2025) introduced a synchronous version of its resolver hook registration API (`module.registerHooks()`) specifically to improve performance over the old async `module.register()` API. It was a big unblocker for Nub. For the interested, the async API added 19ms fixed registration overhead + about 130us additional overhead per import.

Which flag Nub uses here doesn't impact userland at all, TLA is supported wherever it's supported by Node.js itself.

Thanks! From what you say here and what I see in the docs, it looks like everything is much simpler and more robust than when I was exploring the space. I’m happy to see that, and thrilled it’s mature enough now to support use cases like nub.