A Beta Reader is essentially a person who provides feedback that potentially helps your book to be better than it was. Not everyone can provide that service.
In life we end up with a mixture of successes and failures. To be realistic let your character also experience success and a small degree of failure. Perhaps a victory doesn’t satisfy as much as the character anticipated.
So, PCE is: the practice of examining manuscripts from the earliest draft through the continuous copy editing until the final draft. Then proofing kicks in as the final draft is prepared for publication.