To just the author and mods, unfortunately we cannot support this yet, as we don't have a "post author" pseudo-group. That is a good idea, though.
We did accomplish this via nodebb-plugin-support-forum, you could try this and see if it still works?
I'm setting up a proof-of-concept NodeBB installation to replace a small Simple Machines Forum I run. (I'm not worried about importing because we don't have much content.)
I'm using categories and sub-categories. Is it possible to block posting in a category? For example, I don't want anyone to post a topic directly under "Member Forums", rather they'd go into the appropriate sub-category (like "General Discussion" or "Minecraft") first.
Untick "can create" topic and "can post" in the parent. But not in the child categories. Folder permissions don't traverse down from what I remember.
I will try that, thanks! I wasn't sure if privileges were inherited or overridden by the settings on parent categories.
Kind of hard for me to test as an administrator lol. I can post regardless of settings. I guess it's time for a low-privilege account.