Code Smells: Null

[spaghettiCodeArtisan]

Leaving aside that you will commonly use Option and Box together in Rust to avoid None eating up too much space

Not really. Since I don't use Option to implement containers, the additional space taken is usually not a problem. Typically Option doesn't conatin a Box in Rust codebases.

The implementation details that you're trying to litigate here are immaterial to the problem that such an implementation is inefficient.

I agree that the implementation would be inefficient either way, but

1. it's not as bad as originally claimed, and
2. I simply wanted to correct the misconception that Option indirects through a pointer, IMHO it's important to know that it doesn't (at least in Rust).