Dialog (Modal) Pattern. A question of modality and focus management

I am seeking guidance to understand the tab ring behaviour for non-modal
dialogs that use aria-modal false. This is specifically in reference to the
ARIA Practices Guide for Dialog (Modal)
<https://www.w3.org/WAI/ARIA/apg/patterns/dialog-modal/#:~:text=Like%20non%2Dmodal,closing%20the%20dialog.>

*"Like non-modal dialogs, modal dialogs contain their tab sequence. That
is, Tab and Shift + Tab do not move focus outside the dialog. However,
unlike most non-modal dialogs, modal dialogs do not provide means for
moving keyboard focus outside the dialog window without closing the
dialog."*

*https://www.w3.org/WAI/ARIA/apg/patterns/dialog-modal/#:~:text=Like%20non%2Dmodal,closing%20the%20dialog.
<https://www.w3.org/WAI/ARIA/apg/patterns/dialog-modal/#:~:text=Like%20non%2Dmodal,closing%20the%20dialog.>*

For a non-modal dialog, for example an information sheet, that is
non-critical, how should this work. What recommended practices are there
for the keyboard user to interact with the main screen without dismissing
the modal. Would being able to minimize the dialog be an accepted means to
enable access to the main page content. Would a button that the user can
click to move to the main page content be sufficient.

What is the recommendation for focus management when the user is focused in
the main content and how do they return to the dialog? Is the only way to
access the dialog content clicking the triggering button?

I have these questions swirling around in my head and seek clarity in what
recommendations to make in regards to accessibility for a non-modal dialog.

Thanks in advance.


Laurence