Yes, you can drop luggage at anytime once the port is open. 11am to be safe.
Although regardless of your PAT, you could likely board around 12:30 - 1:00, regardless of PAT, when general boarding is opened.
You chose a Port Arrive Time, PAT, not a boarding time.
General boarding usually begins around 12:45 pm.
Then you can walk aboard regardless of PAT, Boarding #, or anything.
Don't wait till 2:30 to get to the port unless of course you have to.
Show up at 12:00 noon or shortly there after.
That is the sweet spot for little to no lines.
JMO
HTH