I'm having the same problem, and just posted my question too. The guide is a bit hard to follow where it explains Grouping. They tell you a bunch of code, but don't really explain when or where to put it or what the expected results are. I almost reads like it does the opposite of what I think they are trying telling me what it should do.

Read through some more of the guide, it is buried in there and not too clear. Try this:

In Custom Data of the LCD block, or the Cockpit:

Power T:*
Tanks T:* Hydrogen
Tanks T:* Oxygen

The Screen is blinking on mine, I guess when the code updates, but it does seem to reflect the status of Only the docked ship.

Maybe use the script's slow mode on these ships so the screen doesn't blink as much?