This may be old news for some but I found my first one today. The setup program of Legend Entertainment's "Death Gate" is nice enough to ask you what instrument set you would like to use upon selecting Roland Sound Canvas during config. Here is a picture, courtesy of DOSBox:
I am guessing this may be true as well for some of Legend's other games (e.g. Shannara). Too bad I don't have an SC-55/88 to test it. Does anyone know about other games with such specific support?