A thing that looks like a 3.5mm dummy plug.
Each one has some LED indicators, and each has a unique ID.
They act like cordless patch cords. Bidirectionaly, electrically transperent.
~5 meter range. Long battery life. Maybe parasitic power?
A local (not cloud) little box configures the plugs, talks to an app,
and also acts as a charging and enrollment station.
One-to-one and one-to-many connections.
Each has an amplitude and offset, perhaps some modulation.
Named groups and load/save of presets.
$240 for the starter box, $17 each for plugs.
Just plug 'em in. Everything but with no wires in the way.
Of course they'll never/can't be made, but wouldn't they be fun?
noodlehut.bandcamp.com