Doesn't work right:
Place a pump, or a ghost of a pump, near the ghost of a train track. It does not show the correct graphic for the pump.

Works right:
Place a pump, or a ghost of a pump, near a placed track. It does show the correct graphic for the pump.

After you start the game, you are on the main game menu. From there, press ctrl and numpad+ or numpad- to adjust the UI scale. This is a well known easter egg to look at more of the funny background situations happening behind the menu.

Keep the main menu on an extreme scaling option (i.e. scaled ...

There seems to be a bug with the stack size. The stack size override is enabled by default (instead of being disabled as expected) and it's set to a stack size of 1.

I created a simple looped belt to test it, with maximum load on the belt, and was able to show that the stack size WORKS for 1 tick ...