True. I'd rather have dots instead of spaces.

That would at least be somewhat intuitive.

How would you do a key that contains a dot? :-)

Quotes? Escape the space?

Whoa yeah agree, as YAML would give you something completely different:

    {
       "outer middle inner": 3
    }

TOML has a similar feature.

CUE appears absolutely stuffed with features. If there are any misfeatures, apart from having so many features, they don't jump out at me.

For me having too many features IS a misfeature.