O.M.G.!!!
Mystery solved!
Scutters, you know, in all those past years it somehow never occurred to me that "Launch" and "Start" are actually two different commands!
Even more important here is the fact that I was always under the impression that all these "1980s Tables" etc. filters would appear below the ""Return, Exit, Shutdown, Restart" menu...
Pressing "Enter" on the keyboard / newly assigned cab button of course brings up those menu selections where I also can introduce new filters via the Game Manager's "New List" procedure.
The solution was right in front of my nose the whole time...
So thank you one last time for clearing up that "mystery", and now it's back to hitting the silver ball.
Have a great day and keep up the good work!