Scroll down for an improved version
After seeing the design by Sikerow which proved that a 1x1 12 stacker is actually possible I decided to mess around and try to create my own design. I ultimately created this - the key was having 4 stacker groups on the bottom and 2 on the top instead of 3 on both the top and bottom which permitted a clear middle row that could be filled with launchers and also made the connection logistics simpler. This should be a lot cleaner than the other design and as an added bonus there's no launchers going through stackers so it should be more resilient to future collision changes (assuming they don't do something like make launchers collide with the bottom of conveyors ☹️).
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