There is a problem with the 'Transform to audio' when transforming an Impact XT track with multiple outputs selected. (probably the same for other multi-output instruments). It transforms to a single stereo track. At undo, you loose all inserts and sends too.
It is not possible to bounce a multi-output instrument to a single stereo file, while maintaining all properties. And there is most of the time a reason why multiple outputs we're used. Like different effects (sends) for example.
The only workaround now is, one by one, bounce the tracks (channels in this case) to new tracks or explode pitches and then bounce each of the newly created tracks.