My Boses allow you to set the cancellation level with a button press. It cycles through three options: high, low, and off. Does the app enable more fine-grained control or something? Perhaps per-ear cancellation settings?
Apparently so. I have the QC35 II, which has a button on the left ear can. Bose calls it the Action Button, and it's used to summon Alexa/Google Assistant; but if you don't configure it to use an assistant (through the Connect app?) it will cycle through the noise cancellation level settings.