Multitimbral MIDI Confusion - Particular VST

I hope this is as good a spot as any.

I was wondering if anybody has a theory as to why multiple outputs works well with Halion versus, in this case LuSH-101.

In Halion SE, I can load 5 channels with separate sounds. I set the sub-outputs for 1-5, and add a MIDI channel for the remaining 4 tracks. Channels are now MIDI 1-5. When I play individual channels, only that channel transmits data.

Unlike in LuSH-101, with the same setup process. Channel 1, the main out, always shows a MIDI indicator no matter which channel is selected. Could this be a result of how the VST was programmed. I’m trying to learn exactly how MIDI works in Cubase and this is throwing me off a bit.

Thanks for any insight.