Here's the proof - no cables attached:

Wow, it looks great! It even looks better than a lot of kickstarter "prototypes" ;)

While things look better now, the initial poor results may indicate
that a stronger battery may be needed. The boost converter could
also run from a single AAA cell (which would require only a
moderate size increase) but the current unstabilized battery
voltage rail (MCU and RF) would have to move past the/a converter,
which means that the converter would be continuously active.

You've more experience than me in this business, but I've in my "to test list" the bq25504
 from TI; according to specs, it has decent efficiency with even less than 1V power and 10ua current: