PLEASE allow the editor to choose whether or not tracks are added to the current sequence to match the tracks on the source. Most editors spend a lot of time configuring their sequence, and most sources have varying numbers of audio/video tracks. Automatically adding tracks to the sequence on source load with no option to first patch the desired source tracks to the prescribed sequence tracks opens up opportunities to add unintended source elements and make the sequence unmanageable in terms of number of tracks. Solving this issue by modifying all the source clips is untenable, as you cant even screen them without loading and causing unwanted track additions. It could be a preference setting to toggle track adding on or off.