Premiere Pro Auto-Save location and interval: keeping recovery files usable across project format migrations

Goal

I want to configure Premiere Pro's Auto-Save so that recovery files remain usable even when a project undergoes a format migration (for example, opening an older .prproj in a newer Premiere Pro version that upgrades the project schema). The specific concern is whether the autosave file written after the migration can still be used to recover work if the migrated project is later closed without saving or becomes corrupted.

Current understanding and constraints

As I understand it, Auto-Save writes a temporary .prproj autosave file at a configurable interval (1–99 minutes, default 5) via Preferences > Auto Save, and the location can be changed from the project folder to a custom path. The autosave captures project state at the moment of the save, not unsaved edits beyond the last manual save point.

What is unclear to me is the compatibility boundary: once a project is migrated to a newer schema, does the autosave file inherit the new schema (making it unreadable by the older version), and does pointing Auto-Save at a custom location change anything about naming, rotation count, or cleanup behavior?

Questions

• After a schema migration, is the autosave file written in the new format only, or is any backward-compatible copy retained?
• Does a custom Auto-Save location affect how many autosave generations are kept or how they are named?
• Is there a documented way to verify which schema version a given autosave file contains before relying on it for recovery?