Persona 3 Reload has unusually useful public Steam Cloud metadata: SteamDB shows the exact WinAppDataRoaming root and SaveData*.sav pattern. That makes the Steam backup boundary clear, but it does not solve Microsoft Store compatibility because the Game Pass version lives in WGS and community transfer workflows use conversion/encryption-aware tools. SaveEditor therefore documents both locations while explicitly separating “where the file is” from “whether it is directly compatible.” A safe migration starts with a complete backup of both source and target directories.
Which storefront context matters
Documented Persona 3 Reload PC launchers/storefronts: Steam, Microsoft Store. The Steam and Microsoft Store save containers are not equivalent. Do not rename an arbitrary WGS file to SaveData001.sav and assume it is valid. The active storefront/account should be identified before any restore because cloud and local storage may not use the same path or container across editions.
Documented cloud behavior
Steam Cloud and Xbox Cloud are documented. SteamDB reports a 550 MiB cloud quota and the SaveData*.sav pattern for Steam. Cloud synchronization is useful for continuity, but it can also turn a restore into a conflict-resolution event. Let synchronization settle before making a manual backup, and keep an offline copy outside any folder monitored by the launcher or operating-system sync service.
Local save roots still matter
The researched local save boundary is Windows: Steam: %APPDATA%SEGAP3RSteam<64-bit-SteamID> ; Microsoft Store: %LOCALAPPDATA%PackagesSEGAofAmericaInc.L0cb6b3aea_s751p9cej88mtSystemAppDatawgs<user-id>; the known file or folder pattern is Steam: SaveData*.sav; Microsoft Store: opaque WGS files/containers.. A cloud-enabled game still has concrete local data involved in ordinary play, and that local context is what you need when identifying which copy was modified most recently.
Avoid accidental overwrite loops
Copy the complete Steam-ID directory or the complete Microsoft WGS tree before any transfer. Keep original SaveData files untouched until the migrated save has been loaded and re-saved successfully. When restoring, close the game and launcher, preserve both the current local copy and the backup you want to test, then place the intended data in the matching profile/storefront location. Do not repeatedly open the game between different copies without noting which side the cloud client selected.
Compatibility and conflict checks
Game Pass-to-Steam migration can require encryption/container conversion. The existence of both files on disk does not make them byte-compatible. If progress disappears or rolls back, If Steam does not show an imported slot, confirm the 64-bit Steam ID folder and SaveData numbering. For Microsoft Store migration, restore the original WGS copy if a conversion tool fails. Resolve identity/path/cloud questions first. A cloud conflict is not proof that the save itself is corrupt, and a successful upload is not proof that files from another storefront are compatible.
Verification context: Reviewed against PCGamingWiki Persona 3 Reload and current SteamDB user-file-system mapping for app 2161700.