Instant Prompt compatibility with prompt-modifying themes

Instant Prompt is a documented performance optimization in Oh My Zsh that renders a cached placeholder prompt immediately and replaces it after initialization completes.

The framework loads plugins and themes by sourcing oh-my-zsh.sh from the user's ~/.zshrc configuration, with load order determined by the plugins array and ZSH_THEME setting. Instant Prompt compatibility with themes that modify prompt escape sequences is described as an unresolved design decision and is not universally enabled by default.

Because replacement behavior depends on how a theme constructs and updates escape sequences, the conditions under which a theme can be used safely with Instant Prompt are not clearly defined.

Does Oh My Zsh document explicit compatibility criteria for themes with Instant Prompt? Which categories of prompt escape patterns are considered risky for placeholder replacement? When is Instant Prompt considered safe to enable by default for a given theme?