I have the deluxe frame and the brackets are not at the corners but in some on each side, similar to what you saw on the 1.5" frame. I have the 92" screen so my measurements wouldn't help much. While I think you probably could use some heavy duty anchors in the wall I decided not to go that route. My wall was already finished so I couldn't try the stud route either.
All you really have to do is mount two 2x4's across some studs for support (one towards the top and the other towards the bottom. Then mount the brackets to the 2x4's. The screen will hide them from view, plus it will make the screen appear as if it is floating in front of the wall. In addition, you would have space to mount bias lighting behind the screen, if you so choose. While I used 2x4's, even strips of 3/4" plywood would work if you think 2x4's are too thick. Lastly, it takes no pre-planning just in case your design changes some along the way (my sure did).
All you really have to do is mount two 2x4's across some studs for support (one towards the top and the other towards the bottom. Then mount the brackets to the 2x4's. The screen will hide them from view, plus it will make the screen appear as if it is floating in front of the wall. In addition, you would have space to mount bias lighting behind the screen, if you so choose. While I used 2x4's, even strips of 3/4" plywood would work if you think 2x4's are too thick. Lastly, it takes no pre-planning just in case your design changes some along the way (my sure did).