Project-wide settings live in Edit > Project Settings > Persistent Asset (or Tools > Persistent Asset > Settings), split into the sections below. You should commit the settings file to your VCS.

The Persistent Asset settings page
Edit > Project Settings > Persistent Asset, all sections in one place

General

Default Persistence ManagerThe manager assigned to a newly created persistent object (default: Prototype). Set it to None to create them with no manager.
Default SerializerThe serializer a new (or reset) manager starts with (default: Unity JSON).
Max Drain Time In Editor
Max Drain Time In Build
Hard ceiling, in seconds, on the shutdown drain when leaving play mode and when quitting a build (5 each by default; 0 means no ceiling).
Auto Lock On BuildWhen a build automatically locks every manager's breaking fields: Any Build, Release Build (default), or None.
Prompt Before Auto LockWhether the automatic lock asks for confirmation first (off by default; a command-line build never prompts).
Editor Default Slot
Slot Name
Editor convenience: the toggle seeds a starting slot (named in Slot Name) so a multi-slot object works when you press Play straight into a gameplay scene. Off by default, ignored in a build.

Singleton

Generation FolderEditor only: the folder where a PersistentSingleton asset is auto-created for each of its subclasses (default Assets/Persistent Singletons).

Security

Cheat Protection SecretThe secret the encryption and integrity key is derived from (see Securing saves). Generated automatically, unique to your project; changing it makes every existing protected save unreadable, so commit it and keep it identical across builds.
Ignore Runtime Secret In EditorEditor only: lets a manager whose Lock Save To includes RuntimeSecret be played in the editor without the runtime secret your code provides. Builds always honor the lock.

Remote

Push Retry DelaySeconds between attempts to push pending offline-cache data to the server (default 30, clamped to at least 5).
Request TimeoutA hard ceiling, in seconds, on a single remote request, a safety net against a server that accepts a connection but never answers (default 120; 0 disables it). Normal operation is governed by each manager's own Load / Save / Clear Timeout, which usually ends a request first.

Variables Binding

Binder Poll DelaySeconds between a Variable Binder re-reading its bound components for changes. Defaults to 0.1; 0 means every frame, at a per-frame reflection and allocation cost.