EDIT: It seems @inspectortalon and @maidofmoss figured this design out before I did! Be sure to check them out!
Here I present two designs for 1wide, tileable stacked minecart separators. These designs are extremely simple and compact.
I first saw the design by @inspectortalon featured at start of video in CartMIS™ by @RaPsCaLLioN1138 and Talon:
• 16x Faster CartBased MultiItem Sort...
Check out @inspectortalon for great videos on minecart tech!