Well, I found for myself that copying a MIDI in port to another MIDI in port, for example the GP local port, at gig script level is not optimal.
When trying to learn a widget to a MIDI command, it always takes the copy, not the original, for which all CC alias are definded in the rig manager.
I found a better solution, hopefuly. Including the MIDI LED activity scriptlet in a gig script, and sending the activity flag via a CC by the GP local port to a LED widget which could be anywhere.