PhpStorm 2025.x upgrade rollback: restore the previous config directory or reimport settings from scratch?

Recovery decision after a failed PhpStorm upgrade

After upgrading PhpStorm through the JetBrains Toolbox App, I want a safe rollback path if the new build misbehaves. I understand the IDE keeps settings, caches, and plugins in version-specific directories, so the previous build's configuration normally survives an upgrade, and Toolbox retains earlier builds under "Other versions" for downgrade.

What I cannot decide is the cleaner recovery strategy once I roll back: point the old build at its untouched previous config directory, or start fresh and reimport only an exported settings archive (File > Manage IDE Settings > Export Settings). The concern is that the newer build may have already migrated or partially rewritten shared state — plugins, project-format settings, or caches — leaving the old config in an inconsistent state.

Assume a recent PhpStorm release on a desktop OS, with exact config/system paths verified per JetBrains documentation for that version.

• After a failed upgrade, is restoring the prior version's config directory wholesale considered safe, or can the newer build's migration contaminate it?
• Does reimporting an exported settings archive into a fresh config avoid plugin compatibility problems better than reusing the old directory?
• Which approach minimizes the risk of losing local history and run configurations?