The scenario you describe is already a disaster, though! Who let that slip through? Replying to a message should create an idempotent context that can't run away from you. "What a mess!" as the kids say.
I'm not a user of smart earphones but lots of things like that should be on the table. Decades ago we were waiting for small cheap cameras and CV to do focus-follows-gaze and just kinda forgot about it when the stack arrived.
There are more "pinch to zoom" type revolutions available to those with a studious HCI methodology. Even Academia seems to be chasing "latest craze" development now, not fundamentals.
I hope your experiment succeeds!
My take on the bias toward the “latest craze” is that it's probably a result of finite attention spans, as well as a fear of falling behind, which leaves little space for fundamental concepts.
A good example for ScrollPods was to support scrolling only through up/down head movements initially but many users asked for left/right head turns to map to vertical scrolling as well. Once implemented, the horizontal axis felt much more natural and less tiring. Thinking about it deeper, this makes perfect sense from a biological and anatomical perspective. I mean humans would probably be way more concerned with an ambush from a predator from the side or behind rather than above which shows in our peripheral vision for horizontal versus vertical visual field.
You can’t scroll in one window and type in another window at the exact same time. Your hand has to stop typing on the keyboard, move to the mouse and then scroll. There are many cases where a user would want to scroll and type at the exact same time without needing to keep switching back and forth between the keyboard and mouse. I then describe a solution to this problem. I hope this is clearer.