How low power is it - it all depends is the correct answer. The chip is tuned for a few different application scenario:

1. DVFS mode: Here you select a clock speed/voltage your application require - and you will get the associated voltage/clock speed in return. You can doctor your code with calls to have various performance levels.

2. Deadline based: You select a deadline for the work to complete within - and the device will throttle by setting clock speed to match this requirement. The voltage is matched for the selected clock speed.

IO voltage is maintained from a seperate regulator - so internal logic voltage can vary with stable IO voltage.

Mask rom + flash...why? Maskrom for some secure boot stuff, stdlib and math - it is less energy per fetch from mask rom vs. flash. Ideally everything should be in ROM - but that makes it hard for the end user to add his/her application

Does it have the RF harvesting bits built in? or is it a bunch of passives that I have to add after.

How low power is it? are we talking microamps per mhz(I know we're not...) How much useful time do you have per charge cycle?

the articles section seems to be full of generic health mumbojumbo, which isnt a good start... https://www.onio.com/article-list.html

Even 32kB of rom is going to be very tight to fit a wireless stack like BTLE. It’s not clear if their BTLE peripheral includes the stack or just the radio. I would hope it’s the latter.

They have open positions on their career page: https://www.onio.com/career.html

Seems like a great time to join this company and help make this product come alive after years of work. I would guess they are an efficient and driven team where everyone knows everyone else.

I am not affiliated with them, but working at companies when they start to gain traction and to feel how proud everyone is at getting a product out with a relatively small team is great fun!