I searched around and this kept coming up as the first search result. Couldn’t find a great answer anywhere, but then an idea struck me and I tested a few things.
Turns out that when you use GetBounds (Steam VRChaperone component) (or Oculus Boundary’s GetPlayAreaPoints), the first two points you get will be the front left and front right points of your room.
From there, you can find the mid-point (a.k.a. forward point / “front”).
Next you can get the forward vector of a look rotation from the player start position to that mid-point and you have a forward point 
Happy coding!