Thread:Project:Support desk/Can sub-categories filter hidden the same as super-categories

I'm using API for retrieving super-categories via "&prop=categories" query and sub-categories with "&list=categorymembers". The former can filter out hidden categories (clshow=!hidden), but latter not. The easiest way to check whether one of sub-categories is hidden is by checking for every item of the result whether it belongs to "Category:Hidden Categories" (with query prop=category and clcategories option). But this increases the traffic significantly and slows since a bunch of sub-categories comes as the one result (300 milliseconds for en.wikipedia queries at my location), but checking will require 300ms*NumberOfItems

So, is there other way? Or if not, can the api &list=categorymembers be extended to support hidden also?

Thanks