@sparseMatrix

I found something in a recent FAQ that says I should add an article instead of a post, but the option to add an article is not on the menu on my instance

Looks like what you found was just outdated. It used to be "article" because of the whole magazine themeing, but people found that confusing so they changed it to "thread". Because, you know, it'll show up in the "threads" tab. So the correct option is "Add new thread".

The short story is, the microblog here is essentially a right pain in my ass.

If you get yourself a userstyle extension/addon for your browser (like Stylus for chromium ones), you can hide the tab if you don't want to see it.

This should work:

menu.head-nav__menu > li:has(a[href$=microblog]) {
   display: none !important;
}

Assuming your browser and version supports the :has() selector, as it's relatively new. You can check support here.

This will remove the "Microblog" tab from the list, though other links to it will still get you there. So if you do want to see the tab for some reason, you can still just add /microblog to your url manually.