I’m trying to understand the purpose of $stream_by_category
If I read the docs correctly & from some try outs
it produces new streams $category-[category] containing linked events to the *only the first event of each streams *in a given category ?
$by_category that produces new streams $ce-[category] that links to *all events of each streams *in the given category.
So anynone uses *$stream_by_category *and what for ?