Sounds reasonable. But I guess that's my point. You'll never pressurize a room in a residential home by pushing air. Like the old saying, you cannot push a rope. But pulling a rope (negative pressure) always works. RA>SA.Well opening the master bedroom door should eliminate a positive pressure problem, and that door is open almost all the time. So I should be able to 'push' more air into the room and whatever won't get 'pulled' out by the air return should simply go out the door and be sucked into an air return somewhere else??? It makes sense, following Boyles law, simply because the whole house must be of a constant pressure so if one room is 'over-pressurized' then it should push that air out the door and into the remaining house.
I did think about installing a duct booster in the return air vent.
But I think installing the duct boosters in the 2 vents on the wall is a better option simply becuase of the contortions those ducts go through to reach that wall, if each 90-degree bend is equivalent to 10' of drag, then that air is travelling something like 100' to 110' from the furnace to the bedroom wall.
By placing the fans near the supply register, you are effectively pulling more air thru the SA ductwork. And the many turns. So the number of turns is moot either way. But either way, a good thing.
BTW, where is the T-stat located. Means nothing to this exercise, just curious.