So I manually busted out a drum part across several MIDI tracks for SD3. I muted all but one and Solo'd that track. SD3 doesn't solo in the synth rack...so no sound.
 
Okay. So I solo SD3 in the rack, which solos all the MIDI tracks. I then MUTE all but one track...still no sound. MIDI meters show activity though.
 
Oooookay, so I solo all the SD3 tracks, then clip mute all the clips in all but one track. No sound.
 
Anyone ever encounter this? Wondering how I go about bouncing down all the parts individually.
 

Using drum maps?

Nope, just straight up SD3 with MIDI and a single audio track for the output. I manually cloned the track and deleted all but one range of notes from each one to get each part of the kit "broken out" to it's own MIDI track. No linked clips or things like that. I reckon I'll just close and re-open and see if it breaks the dependency.
 
What's weird is that I just did the same exact operation on a group of Battery tracks and a groups of SD1 tracks and it worked fine.