Hello. This has already been asked by someone else, whether they can hide subcategories from home page but the response was to modify the CSS. Could there be a feature which could hide the subcategories without having to modify the CSS?
Subcategories are presently only supported by the vanilla theme, and even then it's all on the backend of things. The Child categories don't acutally show inside of the parent categories...yet.
This should be a simple tweak though, as @a_5mith mentioned to me the other day.