Sub-busing on internal bus

[evglep]

I see in the documentation it is not possible to split internal bus.
I am curious why this is the case?

[WBahn]

For "why", you would need to ask the authors.

I'm guessing it was just a consequence of how they happen to write the emulator.

While a bit inconvenient, it not a big issue since you can output the same signal from a part multiple times and you CAN tap parts of buses there.