Configuration
All behavior lives under System → Plugins → System - RCA SPPB Compat in the Feature switches fieldset. There is no hidden magic elsewhere. Save after every change and retest the workflow that switch controls.
Media patches
Leave this On when you need Media Manager to see both the SP Page Builder files folder and the normal Joomla images folder on Joomla 6, and when you need the Joomla 6 filesystem class name repairs in the patched admin files. This switch is a CODE HACK. When On, the plugin may rewrite up to six files under administrator/components/com_sppagebuilder/ and write .rca-orig backups beside them on first change.
Patched paths when Media patches is On
The relative paths are editor/helpers/SecurityHelper.php, editor/traits/AppConfig.php, editor/traits/Media.php, helpers/media-helper.php, models/media.php, and views/media/tmpl/folders.php. Turn Media patches Off if you want zero on-disk SPPB changes and you only need Article checkout or Options fixes.
Article checkout
Leave this On unless you do not care about Save and Save and Close after you leave the SP Page Builder editor and return to the normal com_content article screen. This is the former Article Checkout plugin job. It checks out the article so Joomla shows the toolbar again.
Options field path
Leave this On so SP Page Builder custom Options fields load correctly under Global Configuration. This is part of the former Config plugin behavior.
License update sync
Leave this On so empty JoomShaper license fields do not write a broken update site row. The plugin only writes license details when there is real data to save. This is the other half of the former Config plugin behavior.
Diagnostics
Leave Diagnostics Off on production sites. Turn it On only while you are debugging Options-related behavior and you are actually reading the PHP error log. Do not leave it On because it sounded useful.
After you change a switch
Save the plugin, clear Joomla cache if your site uses aggressive caching, and retest the related admin workflow. Changing switches without retesting is how you collect mystery tickets.