NRF52840 + Zephyr power states.

Hi all. I hope you are well!

page 56 in this document: https://infocenter.nordicsemi.com/pdf/nRF52840_PS_v1.1.pdf seems, to me, to be listing a bunch of different power states that the nrf52840 can be put into. 

I have been digging around in the zephyr RTOS code (version 2.5.99)  and it seems that the only power states that are implemented for nrf52 is OFF and the normal operation mode.

I don't know if Nordic is contributing to the development of Zephyr, but if you do (or know they do) do you think it is on the plan to add support for more of these states? Alternatively, if some hobbyist is to attempt it, how much work it be? Are the lower level nrf HALs used by zephyr prepared and in a good state to set these modes, so that the issue is just about glueing some zephyr concepts to the underlying hal concepts?

Thanks a lot and have a great day!