I stumbled across this setting while doing some reading and experimenting about how to make my discourse forum’s more user-friendly for newcomers (and myself).
I really like this single “New” view which one can split into topics or replies.
Seems like a more intuitive meaning of “New” to encompass both “Unread” (that is, new replies on tracked topics) and “New” topics (that is, topics that have been created recently). Also close to the “hybrid unread+new filter” that @sam mentioned years ago here.
Is this still experimental and is this topic the only one about the feature?