I have 2 x w1070 stacked setup (one ontop of the other)
Filters fitted inside, vns geo 201 demuxer. one has slight green tinit, the other has slight violet tint, but can adjust MOST of that out when just using one for 2d video.
one appears to be slightly dimmer/darker, but again just adjust contrast or brightness to compensate.
To be able to get them to line up really (Not perfect) I removed one of the w1070's adjuster screws sliding cover to get both of them as close as possible so not having to use alot of offset.
Only issue I find, is I now get alot more light leakage coming out of the front and side vents which show on the ceiling and side wall, seems the filters maybe the problem as wasn't anywhere near as bad before fitting them inside the w1070's.
One day I WILL make something to sit infront of the vents which will defuse/block the light, yet still allow the heat to escape.(using black spandex and brackets)