The bridle is very important to the sound and strength of a cane drone reed. The length of the tongue is adjusted by moving the bridle the same way as a synthetic reed. Movements, however, are not as critical as a synthetic reed and can be bolder whilst finding the correct position for the bridle.
The tension of the bridle is critical to stability and sound. Too loose and the reed will sound dull and will likely move with pressure variations. Too tight and the reed will most likely squeal when striking in. Tied at the correct strength will make the reed brighter and more stable. It’s worth tying some bridles at different strengths to hear the difference.