The point comes out great because it has more fat. The flat is leaner, Select grade even more so than Choice. You don't say if you are adding any liquid to your wrap. If not, add 1/2 to 1 cup of beef broth just to keep it simple.
There are three sources of moisture in meat; water, rendered fat, and melted connective tissue. Briskets, tough cuts of meat, get the majority of their final moisture from melted connective tissue, but rendered fat plays a role too. Water evaporates out of meat in a hot environment and the stall is evidence of that occurrence. In fact all liquids in a cut of meat, water, rendered fat, melted connective tissue, will flow out of the meat if left in a heated environment long enough.
Try experiments just for experiment sake and change only one variable at a time.
First experiment, do everything the same as you described above and try probing it sooner, say 195F, and probe it every two or three degrees in temperature climb until it is tender. You may even need to go as high as 207 to 210 IT, but I doubt it. Pull it off when tender, leave it wrapped, surround it with old towels and let it rest for an hour or more allowing some of the juices to be pulled back into the meat as the meat relaxes and cools.
2nd experiment; wrap it sooner. Try wrapping it at an IT of 150F with a little beef broth. Start probing at 195F IT. Probe it again like you did above. When tender, remove, leave it wrapped, cover with towels and let rest an hour or more for the same reason as above.
Last experiment; injection. Using the initial smoking process you described above, inject it with beef broth before smoking. Then do everything the same as you initially did wrapping at 170F with a little broth. Start probing at 195F again and continue until you get tender meat. Rest the same.
All three of those should provide you with a moist product, and you may find you like a combination best to suit your tastes and needs.