It will be a very interesting exercise for you.Thankstallbm , that is absolutely helpful..I used the pervious 200 degree temp to start probing the meat for tenderness, but the tip about using multiple probes isn't one I had considered..my inkbird has 4 probes, so I'll do 3 in various parts of the flat..I know the feel I'm looking for based on probing that last brisket, but I'm sure I can make it better..
I FIRMLY believe probe placement is the main reason why people have accounts of a brisket being ready at 215F and other reported high temps.
Now I do think each piece of meat is different. However, I personally find the most common occurrence for such different finished brisket temps to be probe placement. It's just hard to get 1 probe in the most precise spot.
When I have Prime briskets I start to check for tenderness at 198F with 3 probes. When I have choice or select (select is rare to have in my area) I start checking at 200F with 3 probes.
I know for sure Prime are usually tender at a lower temp. This makes sense since the cut of meat is clearly a prime brisket so it makes sense up front that the higher grade of meat should/could be tender at a lower IT :)
Give your approach ago and it should be very educational.
On the brisket you do after this attempt, try 3 probes from different angles all aiming for the same spot and that will be very educational as well.
The best spot to probe on a full packer brisket is the thickest yet center most part of the FLAT muscle. The point will always be tender way before the flat. The flat is always the problem child when it comes to tenderness.
I look forward to what you report back with! :D