As long as you don't mind separating for ascents and you're both decent divers, you shouldn't have any problems on the Palau Aggressor splitting up when you ascend early. The skiff will pick you up when you surface and your buddy can stay with the group until the hour is up. Alternatively, the reef at most sites extends nearly to the surface, so you may be able to follow the group when you run low on air by keeping shallower than the rest.
While it's normally a good idea to stay with the group in order for the skiff to make a more orderly pickup, sometimes stuff happens. When we were night diving Orange Beach off Peleliu, I blew through my tank in a half-hour trying to get a couple manually focused macro shots in a strong current. Somehow I got separated from the rest of the group when the current blew me in one direction and everyone else in the opposite direction. By the time I ascended, I was quite aways from the boat which was following the other divers' bubbles/lights, and the boat driver had his back turned so he couldn't see my lights on the surface waving at him. I almost used the Dive Alert, but he fortunately finally either saw my lights or heard my screams and came to get me before I drifted around the point and out to open ocean. If they're that capable of rounding up stray divers on a strong current night dive, you should have no worries about separating from your buddy on the standard daytime drift dives.
