It seems to work ok when I test i manually with the same file as above.

However I have 9 tracks in the mixer 1 Bass, 2, Piano, 3 Drums - Alt+5, 4 Guitar 1, 5 strings, 6 Guitar - Alt+8, 7 Soloist, 8 Thru, 9 Audio - Alt???)

I need to mute all and then enable the Drums and the Audio track.
Then I get the single drum track in the midi.

However I can't find any Alt key for the Audio track, the manual for hot keys stops at Alt+9 but that will enable the soloist track, I haven't found any for the Audio track.

I also guess that all MGUs must have the same order of the drum and audio track in order for the script to work if I can find an Alt key for the audio track.