Whether user settings can be read and written right now (a signed-in user on a metadata-bearing provider).
The user's choice for a channel (key matched case-insensitively), or undefined when they made none.
Records the user's choice for a channel. undefined clears it (back to "no choice").
The default store: persisted in the signed-in user's settings (
MJ: User Settings, key VISUAL_PERCEPTION_SETTING_KEY) viaUserInfoEngine, so the choice follows the person across devices; kept in memory when there is no user to persist for (an anonymous principal, a connect-only embed).Writes always go to memory first, so a choice takes effect and is read back even if persisting it fails or is not possible. Reads prefer the persisted value when persistence is available, since
UserInfoEngine.GetSettingis a synchronous cache hit that already reflects a pending debounced write.