[WorldMaker]

One trick that works better now than at first is that if you need to fallback to CJS for a config file for a CLI tool because it doesn't yet understand the ESM loaders in Node you can just give individual CJS files the .cjs file extension.

I like ESM being the default for .js (which is what "type": "module" mostly does) in a project and then using .cjs files sparingly when necessary (which seems to be mostly just config files for build-time/dev-time tooling with older CLIs today using deprecated loading APIs). That better reflects which is the "present" of JS rather than its past and no need to worry ever about the .mjs bandaid file extension.