Example: In Google Chrome Portable with Portable Passwords enabled, if the user enters the wrong master password or hits cancel, the launcher should abort.
Right now this is only possible with the Abort keyword in the Init function. Anywhere else and you have missed cleanup work! The Init function of course runs before the splash screen, and before the checks for secondary launch and crash detection, making it less than ideal for some of the stuff you might want to do there (in my case, show a password prompt on the primary launch).
I suggest a function you can call that will do any needed cleanup and call Abort for you.
Ideally, if called from the Pre hook, it would not need to do any cleanup associated with the PostExec or Post sections, since the dev can be reasonably expected to not dirty stuff up in Pre until they do their checks for whether or not they want to abort. Similarly if called from PreExec, it's assumed you've cleaned up from PreExec already so you just need Post to be called.
In any event it should skip the Execute step.