I probably need to enable more debugging into the timsplit
But, it's really just for me ...
But, I guessing the problem is that timidity can't process some of the drum tones. If you take your original mma generated midi track and do timidity -Ow somefile.wav somefile.mid (assuming the input file was somefile.mma) does that work?
All that timsplit is doing is generating a series of midi files with different tracks enabled and then using timidity to create a wav.
The other thing to try is to run mma with different tracks like the initial displayed stuff. So, if it is failing on
DRUM or DRUM-KICK try "mma -T DRUM-KICK somefile".
Let me know!
Best.