It’s nothing fancy, but I just released my ‘Publish to Micro.blog’ shortcut version 1.0:

This shortcut uses the Micropub API to publish text passed into it to the default blog on your Micro.blog account. It’s best used as a function that is run from another shortcut.

Take note that there is no preview of the published text with this shortcut so that it can be as streamlined as possible. Check over your post before running the shortcut, or use a preview action in whichever workflow sends text to it.

Get it here from the HeyDingus Shortcuts Library.