Similar, yes, but maybe by very nature of the exit-able-ness (transitoriness) of Bhavanga, that is how it is known to be different than Nibbana?
If you never leave the state of whatever it is, then you would know the craving to do so to be gone. But “you” also wouldn’t “know,” either, because you never leave it. It’s like, how do I know if I’m dead or sleeping? The only way to know is if you never wake up…. But then you’d also never “know,” now would you? Is the craving to “know” what could keep one from actual “knowing”?
Maybe this doesn’t answer your question; if not, disregard