If you need to budget extra time for valet check you've probably got too tight of a connection to begin with.
I would have agreed with this until it literally took 40 minutes to get my gate checked bag at JFK. First no one was there to deal with baggage then they couldn’t get the baggage hold door open. Fun times sprinting the length of T4. Then getting ground stopped on my way to DCA. I wanted like 4 PDBs on that flight.