For post-7.1.GA consideration:

General/Structural issues:

• The general wording of large sections of this guide could do with an extensive rewrite. It looks like a lot was copied from upstream docs that don't really match the voice or style of our guides.
• Chapter 2 "2. How To Set Up SSO with SAML v2" as a heading level seems redundant (it is the same as the name of the guide). IMO, it could be removed, and all subsections be moved up a level in the hierarchy.
• This guide seems to exclusively use the Legacy security subsystem for its concepts and procedures. Does this need to be rewritten to also explain using it with Elytron (or at the very least explain that this uses the legacy subsystem)?

Smaller issues:

• Using abbreviations for SP (service provider) and IDP (identity provider) is inconsistent throughout the book. In most cases, the abbreviation is used, but there are other cases where it is spelled out, without any reason that I can see.