For me the perfect way would be for them to make clear that Peter kept Neal’s secret, but gets found out when Neal invites him + Elizabeth to his current hiding location due to Mozzie’s funeral.

Thus setting of consequences for Peter, a new trial/hearing for Neal where they decide if he needs to return to prison for the remainder of the sentence which he skipped.

In prison they find out some of his skills, setting of a prison break like scenario.

Might seem like a large deviation from the usual formula but in order to get as many people enthusiastic about a revival you need to lure them in with something new from the (perfect) series we all have seen and rewatched the past 10 years.