I just saw some pictures of your current hotspot problem, noob00224, and I'm a little worried there might be one of two issues hurting your current Cinegrey3D; one which can be fixed with paint (or even a second/luckier Cinegrey3D), or the other which might be more difficult to fix.
The goofy thing I'm seeing is that the hotspot appears to be very tall and narrow which is unusual, and that's why I suspect it might be one of two things other than the ALR screen.
1. That material (like the 5D and CarlsALR and the SI Slate0.8 and Slate1.3) is designed to have a lightly wider horizontal viewing-cone and narrower vertical viewing-cone..This is both good because a wide viewing-cone is much more useful than a tall/vertical viewing-cone, AND it's helpful because the projector's throw-ratio is naturally "longer" vertically than horizontally...not literally, of course, but in the sense that the screen is short and wide so a plain hotspot on a plain reflective screen (being round) will be more noticeable side-to-side than top-to-bottom. But the wider horizontal viewing-cone stretches the hotspot into a wider oval shape that makes it more subtle side-to-side.
HOWEVER, these materials come in large rolls from only a few suppliers (resold by the screen companies) and sometimes a clueless company will try to cut the fabric more efficiently to create less waste as they're sizing screens...AND THEY END UP MAKING THE VIEWING-CONE TALL AND NARROW. It ends up the exact opposite of what it was intended to be, hurting both the viewing-angles and the uniformity.
This means a paint could work a little better by default, or any screen material that's cut the right way from the roll.
To be clear, I've heard at least one company (not Elite) openly admit to doing this, at least partly out of ignorance for the way their own material works.
If this is what's affecting your screen, the bright colomn should move left/right (as a complete column) as you move left/right while keeping your height and distance roughly the same.
2. The scarier potential cause, the projector's own uniformity might be poor. This can be made worse by the ALR screen, but it'll tend to make ANY ALR screen look much worse than it normally would. It can be caused by the projector's own optic path being a little imperfect OR it can sometimes be caused by the lamp itself. If the uniformity is bad enough I expect you'd be able to see the slightly brighter white center column even when projecting directly onto the plain wall or a flat sheet. Plus, while the screen's main hotspot will move as you move around, a bright center/column caused by the projector uniformity itself would stay in one place. Even IF this is a problem, there's a chance that a new lamp or even simply re-seating the current lamp might fix or at least improve it.
This is also pretty easy to diagnose once you have somethings to look for (via a sheet or wall, and by moving and seeing if there's still some extra brightness in the center along with the brighter moving hotspot).
I'm kind of hoping for
#1 though since it's most likely easier to solve.