I was on Explora in a DP in January from San Juan. I arrived ~1, there was no boarding until about 1:30. They took some of the residence guest, then some of the penthouse guests, then some OT's. Then repeated the process. Basically they boarded some OT's before me. The time frame was so short as to be no big deal. I went right to my room and it was ready and since I had carry on only, I was good to go.