Validation process
How does Code Cube validate whether an event is a "success" versus an "error"?
This we do based on what we get back from GTM. This happens when GTM flags it as an data.gtmOnFailure() , this happens at a runtime error, a permission has ben denied at the GTM sandbox, a timeout because a tag was taking to long or when the tag template calls this function.
Handling of initiated-but-unfinished events
If a tag initiates firing but the page unloads (due to a redirect) before it can send a final confirmation, does Code Cube default to logging this as an error?
No we don't flag these as an error; more accurately, we don't log these at all.
Meta-specific behavior
Is there any specific logic within the Code Cube implementation for Meta tags that handles confirmation status differently when a redirect is imminent?
No there is no specific logic for Meta tags, we treat them all the same way regardless of the vendor.