Yes, I've looked at those. Both on the particle store as well as Adafruit site. The components on the custom circuitry will definitely not fit on a featherwing board. We would need a custom PCB with a slot for the particle... I also wished Particle sold us headerless Xenons/Borons/Argons but I know the reason why they do not.
But back to the main topic for powering the Particle via LiPo/VBUS. In summary...
- LiPo needs 3.6-4.2VDC. 5V not recommended. This is a pity since most PSUs are within the 3.3V or 5V range. I'll look at sourcing another PSU if need be.
- Debugging via USB while VBUS/VUSB is powered should work if the 5V levels are stable. Else, diodes + disable VCC on USB while powered by VBUS.
I'll keep you guys posted if this works or blows up but if you have any suggestions I'm all ears =)