I have so far unmixed nine audio tracks, and in four of them there were loud noise artifacts in the unmixed version, always within the first or last few seconds of the file (where there is mostly audience noise and no music).
It’s possible to remove these using the eraser and other tools, but of course it would be nicer if these artifacts didn’t occur at all 
Before:
Unmixing using these settings:
After:
Zoomed in:
Should I send you the offending file by PM so you can check if this is reproducible?
Thanks,
Tim