I plan to get some BP, just haven't yet.
I guess I'll start wrapping after I.T.'s get 160-170 and checking it for P.T. like you said.
Also, may need to revisit my "resting / venting" time.
Lots of folks on this form have much more bone fides than I do, but for most of this year I have been cooking a brisket at least 2X a month, usually 3. Where I live (God Bless Texas) I get choice packers for $147/lb routinely. Cheaper than ground meat. I say all that to make a point that when you cook them on a very regular basis, the learning curve is quick.
So....I had about 3 weekends in a row in the spring where I took the flat to 203-205* and thought "gotta be done". And while it was very edible, it was not as good as it could and should have been. I took a weekend off and licked my wounds and gathered the determination to smoke a brisket that would pass the flop and pull test.
Here is what I have learned after about 30 briskets in 2016 (I am not exaggerating):
*If it ain't probe tender in the flat, it ain't ready. If the flat is 250* IT and it ain't probe tender, it ain't ready. I gathered the resolve to trust my probing skills, disregard the probe reading and it has not failed me since. The probe is my guide to start checking and I don't start checking until its 190* for choice.
*Fattier, more marbled briskets will be probe tender at a lower IT. A prime may be probe tender at 198* but a select at 210* Also, not all choice is choice. Since I get a lot of my briskets in the $147/lb meat bin, some of these seem more like select to me. I don't complain at that price, but I give plenty of time for the cook and again, trust my probing skills
*As mentioned, ignore the point. Always ignore the point. Its gonna be good no matter what. Its got too much fat to be anything but good. Yum. I don't probe or check the temp in the point.
*I wrap when get the bark I like. Sometimes that's at ~ 155* and sometimes its at 180*.
*Venting is fine and I recommend it if you are concerned that your flat will fall apart when you slice.
*I have done many with a rest in a cooler and many where I rest on the counter. I think the cooler may help insure proper doneness. My theory is this: lets say you probe several places and find it probe tender in those places, but there are some areas where you didn't probe that are not quite done. Resting in the cooler will hold some high temps a little longer and may end up helping those rogue spots that were not probe tender. This is only a theory.
* I have not found adding liquid when I wrap actually dose anything. It ain't hurting anything but not sure its doing anything, at least for getting the tenderness I am looking for
* I do use butcher paper but that is more for bark preservation than achieving proper tenderness, IMHO. You can certainly achieve a floppy pull tested brisket with foil, a pan or BP. I have done them all.
Sorry for the diarrhea of the electronic mouth. But all that was sitting in my noggin so I thought I would dump it.
Good luck in your pursuit of brisket nirvana.