Really Confused

OK, I just finished up on a thermometer thread about my first brisket I am cooking. It was a huge chunk of meat (16+ pounds) so cut the point off to keep it form taking 16 hours to cook. I have been cooking these two pieces of meat for four hours and the internal temp on both reached 170 degrees. I foiled it at this point as others were suggesting and put it back in the smoker at 225. But even if it takes another three hours (which was the general post foiling guideline I was given) to reach 190+ degrees, that will be only seven hours which is way faster than the 12-16 hours I was led to expect. Any ideas what is going on here? Did cutting off the point cause this drastic reduction in cook time? It is frustrating because I don't have to serve the meat until tomorrow at lunch and cooked it today expecting the long cook time which was not going to work. How should I store the meat for best tenderness and flavor to be served tomorrow? I don't have any cryo packaging. Help a Brethren who is lost in the brisket triangle! LOL!

The Brisket was a smashing success. Yesterday I pulled it when the meat temperature reached 170 and cooked it in foil until it got to 190. I pulled it and let it rest for a few hours and then wrapped it in plastic wrap and refrigerated. I collected the juices in a cup. Today I took the juices and warmed them up and then injected about half of them back into the flat. I then covered with foil and heated it up in a 245 degree oven until the meat reached 165 (about 4 hours). I then re-heated the juices and poured the remaining juices back over the sliced flat and pulled point. The slices had a great smoke ring and we super juicy and tender. The pulled meat was juicy and tasty. The combination of kosher salt and ground black pepper with the hickory wood provided a perfect profile for my taste particularly when adorned with a little Angelo’s BBQ Sauce. It was my first smoking success. No pron because the natives were chewing at my ankles when the thing was done this afternoon. But thanks to everyone who helped with their comments.