One of the main advantages of the project is that user scripts are stored as files, so you could write and edit them using any external editor.

Due to the complexity of maintaining and upgrading the built-in editor, I used to think that perhaps in the future we could abandon the built-in editor, and instead only recommend the use of full-fledged external editors.

But with time, and multiple considerations, I now believe that providing a relatively easy-to-use built-in editor, especially in certain scenarios, still has a non-negligible convenience.

CodeMirror 6 has been around for a while now. This upgrade will be unavoidable if we are to continue to maintain and support the built-in editor.

It's important to note that this is not a simple upgrade, it requires refactoring a lot of things due to the huge changes in CodeMirror 6 itself.

Have other editors been considered? Yes, I've looked into a few, but CodeMirror still has huge advantages, especially for mobile support.

This won't happen anytime soon, maybe in v7.0.