You could get it done,and there are tricks to speed the cooking.
Some folks like to figure 1.5 hrs/lb,and that leaves time for door opening,resting,etc.
Sometimes there are good results,and sometimes not.
Like Smokin' always says,leave plenty of time in the schedule.
You can always hold in a well insulated cooler for three or four hrs.
Setting a couple hrs, seems to help the finished product,anyway.
I have been taught that the more time in the plateau,the better it renders,and the better the breakdown of collagen.
We like to cook at lower temps,and then kick it up in the mornings.
Now, there are excellent comp cooks that cook them much faster.
I like to let the CS finish them all the way,just like I put them in.
If you see you are not going to finish,when you get over 160�,you can wrap tightly in double foil and crank the heat up to your CS max.
That will move it ahead,alot.
If it still is running behind,you can place it in your preheated oven at 325�,and it will finish quickly.
It may also finish ,just like you are planning.