For 2x2 Mode (Hopefully 6x6 will have something similar in a later update)
- Record a track
- Hit next part (either footswitch or midi)
- Record track on 2nd part
- Undo the track on the second part
- Go back to first part
- Hit next part (either footswitch or midi)
- Aeros advances to the next part but does not record. It should (or perhaps somene wants a setting to turn this off, but the default should be treat undone tracks as if they were never recorded).