I'm still a fan of HJSON, and JSON5 looks quite nice, but this does as well. That's all I can really say. There are so many choices, but looks like you did really well on this one.
In my opinion, JSON works well for data interchange, but it's overused for configuration, it's not localization-friendly, and it's too syntactically noisy. INI is simple but lacks hierarchical structures and doesn't have a formal specification. Confetti is intended to bridge the gap.
I aim to keep Confetti simple and minimalistic, while encouraging others to extend it. Think of it like Markdown for configuration files: there's a core specification, but your welcome to create your own variations that suit your needs.