Sortimo T-BOXX rail back

Thank you for making these nifty rails, cnfer!

I found that the rear (back-to-front) rail happens to have the cutout at exactly the position where the back end of the box ends up when I lift the front up so that it can slot into the cutout in the front. If push the box in quickly it'll work fine with the inverted rails, but using this remix for the rear rail means it works even if I go slowly.