SteamVR - How to get room orientation?

Hi all, I’ve been working with Vive trackers and I notice that the Vive Tracker orientation is given by the room scale setup you perform, specifically the white arrow over the green room scale bounds that shows up as soon as you finish to set your playing area.
In SteamVR you can change the orientation of the room so that the arrow points wherever you want, but I would like to get this information inside UE4.

Point is, if I try to debug the SteamVR chaperone, I can clearly see the vertices of the room if I’m wearing the HMD, but I would like to get the same information without using the HMD at all, so just getting the room orientation and eventually rotate the root of the vice tracker accordingly.

The end goal is to have the same orientation for Vive Tracker, no matter what the SteamVR room
scale configuration is.

Is there a way to get that information somehow?

The documentation mention how to get the room bounds, but using the HMD unfortunately.

Thanks in advance