The problem is the rail has trouble working with wings that have roll control cushions like VDH and Oxycheq because the foot of the rail is too wide and won’t fit down in between the roll cushions.
So instead of telling people to cut the roll control cushions off of their nice expensive wings just so they can use the rail, I made use out of the roll cushions that come factory on those wings and incorporated them as an integral part of the design. If you want some angle to the tank I make a simple wedge that bolts on over the wing on the bottom and kicks out the bottom of the tank a few degrees for comfort. Some people can’t tell the difference and some people swear by them. The rail has now been designated as an “adapter” bracket for wings with no roll control cushions, or if the slots don’t line up, or if the wing has no slots at all.