Wait a minute, the "Extension Manager" app from https://flathub.org/apps/com.mattjakeman.ExtensionManager has an "Upgrade Assistant" feature to batch-check all your #GNOMEShell extensions for compatibility with the next #GNOME version, and nobody among you has told me about it?!
And it's not even mentioned as a bullet point in the app's features list?! :psyduck:
This "Upgrade Assistant" hamburger menu item deserves to be more widely known.