Question about Ninja custom build

This is primarily a conceptual question. The docs say Ninja isn’t bundled with Phaser by default, but if I look at the jsdeliver CDN build source (I am using the CDN link in my project) and do a ctrl-find for “Ninja”, it looks like all the relevant Ninja physics content is in there. And if I install phaser-ce via npm in my project, and look in the node_modules folder, that too seems to include all the relevant Ninja code. So my question is: in what way is Ninja not included in the default Phaser CE build? What does a custom build have that the default build doesn’t have?

build/phaser.js doesn’t include the Phaser.Physics.Ninja namespace itself. It does have some references to integrate it when present.

I see, thank you!