Hi there and welcome!
I have that thermometer and I don't belive it has both a High and Low alarm but this one does and has an electronic coupon (just click the coupon) to get 15% off at the moment. It has a High and Low Alarm and 4 probes. I own it and it works well also.
The unit I linked is RF (Radio Frequency) and will work at 100yds no problem.
I mention this because Bluetooth options exist but the range on bluetooth is not as far as a dedicated RF device.
Depending on how far away you are from your smoker Bluetooth may not work for you with it's much shorter ranges but this RF Unit will.
Finally, a 14 pound brisket at 275F in my super optimized smoker would take me a little over 15 hours before it becomes tender and thereby done. Brisket is never done by time or temp, it is only when it is tender.
So your brisket will take way longer than 6-7 hours overnight to finish. Also add an additional 4 hours to your time frame. This extra 4 hours allows for buffer time for the brisket to finish or if it is tender and ready you have 4 hours to rest it. You simply tightly double wrap in foil, then wrap in 3 bath towels and set on the table until 4 hours later when it is time to eat and it will still be steaming hot!
So your 14 pound brisket at a 275F smoker temp naked in my smoker would have me planning to put it on 18 hours before I wanted to eat.
So if eating at noon I would put it on at 6pm the day before I planned to eat. I do this all the time and it works like a charm. To me a brisket is a mandatory overnight smoke if I plan to eat during the day lol.
I hope all this info helps :)