You got it! Thats what the Perfomance mode is for. It allows you to assign different sounds to different MIDI channels. Its the only multitimbral mode on the JV/XP synths.

If you have the INS files for the 3080 for Cakewalk, all you have to do is put the 3080 in Performance mode and you can perform patch changes from within Cakewalk itself - you never have to touch the 3080.