- script_load_addons: loads and onloads all addons, error if any cant be enabled or disabled.
- script_load_modules: loads all blenders modules, error if any modules raise an exception or if any modules in the scripts dir are not tested (except for presets and templates).
These are useful because lazy module loading means a module can have an error which isnt raised until the tools used. This gives a way to detect basic errors that used to happen on startup or when enabling the addon.