Simpler: easy and quick setup, as described in my OP.
Quieter: no rubbing ever - nothing would ever lose alignment, because the electric shifter would continually adjust itself.

ScrubJ...
Compare the weight of a pair of brifters to a pair of plain brake levers. As I stated in a previous post, you typically save 250-300 grams right there! Maybe you'd call that minimal - I don't!

Sensor could easily be piezoelectric of some kind. Very low power, and it would only have to check intermittently for a second or two right after each shift, and then only periodically after that (maybe once every 30 seconds or so). After all, it's likely to be non-changing over the short term (hours) after the shift is completed, so no need for a continuous sensor operation. Not much of a power drain there.