To reiterate, you can manually adjust any GM+GS Sound Canvas to play the click noise (well with an external unit that is), so nothing is "missing". It just won't play back correctly out of the box, if the clicks are indeed the correct instrument in that case.
With lower end units like the SC-7 it'd be impossible to get correct playback as they lack variation tones save for additional drumkits though. So even changing stuff in the MIDI files wouldn't do anything here.
As per queststudios information, I believe that the World of Xeen issues are fixed by simply sending a GS reset before playing the game on GM+GS SCs. Once again it comes down to MIDI driver screwup.