I don't know how big your last packer was but 22 hrs. seams like a long smoke. I have a similar smoker(propane) that I've done many briskets in.
1) Fat cap up or down your choice. ( in my propane unit I normally put fat cap down to shield from heat.In my offset I put fat cap up)
2) Just start smokin it. Smoke it till you get the color and bark you like. Don't even worry about probing it as the IT temp doesn't matter at this point. When you get the color and bark you like (maybe 6-8 hrs) then go ahead and wrap and insert probe where the point meets the flat. Just be sure the prob is in the meat and not in the fat seam. When you get close to the desired IT you want, probe the brisket with a wooden skewer, it should slide in like going through butter. Bottom line is cook till probe tender not IT temp. Each brisket will probe at different temps, start probing with the skewer around 195.
Also, keep in mind on your propane unit the heat goes directly up the center of the unit. You will notice a big temp difference from center to the sides. I always set my chamber temp probe just below the brisket in the center and go by that temp reading.
3) If your going to do burnt ends 195 would be a good temp to separate the point and slice into chunks, then put back in smoker to finish.
4) As far as the flat and point being dry. Yeah it could be you over cooked it or more that likely it could have been the grade of meat you were using. Meat selection is very important. If the flat is very, very lean to begin with, it's gonna be dry no mater what you do IMHO.
The only other thing I can add is just don't try to over engineer or over think things. If your doing low and slow(225-275 or so) nothing happens fast. Just try to keep your temps in a range and let things work.When I'm doing a brisket, I just try to maintain my cooking temp the best I can and i don't even look at the meat for the first 6-8 sometimes 10 hrs.
Hope this helps and good luck!