Apparently they made two different early versions of the Valach CDI unit for the Evo gas engines. The one on the 58GX (first model) apparently didn't have a LED on it. But the unit on my Evo 26 GX engine has a LED on it. I show the pic below with the Evo 26GX engine's CDI unit and its LED cable that is built into it. I copied its layout as I didn't realize they made one without the LED cable. I have attached a screen shot of the hookup instructions for the CDI unit without the LED on it.

Now then I have observed my old Evo 26GX ignition unit would blink once when I turned it on, and then glow when the engine was running. But I don't remember it doing anything else though. I attached a screen shot of the LED blink patterns from the GX2 ignition instructions below.

Both of my ignition units use the spark plugs with their tops cut off and the odd spark plug cap where you use a set screw to lock it onto a inverted cover that is held on with a spark plug. It isn't a bad setup actually, the spark plug is lower down for a lower profile and it stays on pretty good and doesn't tend to come loose.

Yes I can agree that the LED may appear to be on all the time but the data rate may be to fast to see. There is a small four pin IC that may be a driver IC or a optoisolator IC that the LED trace on the ignition printed circuit board comes from and it has a small surface mount resistor on it too. So at the time it seemed reasonable that it was for a LED. But maybe the early Valach CDI units actually were designed to be hooked up to a computer running a program of some sort to communicate with the device. I don't know of course.

I can also agree that the CDI unit appears to be a lot more complicated that I would have thought it needed to be too.

First pic of my Evo 26GX engine with LED cable on it.
The second pic is a LED blink pattern for the GX2 engines using a different CDI unit.
The third pic is the CDI hookup drawing for a GX ignition unit from the instructions manual.