I found the instructions a little scattered, but eventually worked out how to implement the new buttons into my blueprints. As well as specifying the new indieConnector buttons, the layout now also needs to specify the default buttons that would ordinarily be already present also. Here is an example implementation from my 'media' pages:

title: Media

icon: 🎥

num: zero

status:
  draft: 
    label: Draft
    text: The note is still in draft mode. It can only be seen by editors with panel access.
  unlisted:
    label: In Review
    text: The note is online and can be visited with the direct URL. The team must still give the final go to publish it.
  listed:
    label: Published
    text: The note is online and listed in the blog
    
buttons:
  settings: true
  preview: true
  status: true
  icShare: true
  icWebmentions: true
  open: true

My panel view is now much more condensed as illustrated below:

- The buttons replace a number of additional posting and webmention fields, and

- I no longer need a duplicate field purely for direct posting to the fediverse.