@Gordon: it seems like a great idea, but I think I've hit a snag.
I'm running my current code on 1v92.103 (the nightly the last time I DFU'ed) and rigged it up to my Lidl multimeter (only the best quality kit for me...)
After startup but not connected, just advertising, it draws about 0.15mA.
While connected but idle, it draws about 0.35mA.
While sending data and flashing an LED, it draws about 5mA.
All fine so far. However, if I force a disconnect with a triple-click which should trigger an
NRF.sleep(), it'll draw around 3mA steadily!
So, when it's purportedly "off" it seems to draw ten times the power of "on". Not good. Hmm. Any thoughts? Any chance you could give it a go? My equipment and skill level makes these figures somewhat less than conclusive.
(Edit to include photo of my test setup: desoldering braid separated by Post-It note)