Even if local pos gets valid again, the local frame needs to be
re-aligned to a global origin to have a valid global position

Relaxed position is valid as long as a velocity aiding source is active
(e.g.: optical flow or airspeed+sideslip)

Fake pos/height fusion only starts when inertial dead reckoning time is
exceeded and is not considered as an aiding sensor anyway. The dead
reckoning flag is then enough to know if the position/velocity is valid.

This variable contains the location of the NED's origin in global
coordinates. It is then not the global origin but the global reference
of the local frame.

Also, to have a valid global position, this reference doesn't only needs
to be initialized but also valid. It is valid when the local frame is
locked in place by using velocity and/or position aiding sensors.