I have worked around spatial AI for a number of years.

Most of the stuff I have been working with has been aimed at low power consumption. One of the things that really helped is not bothering with dense reconstruction at all.

things like scenescript and SpaRP where instead of trying to capture all the geometry (like photogrammetry) the essential dimensions are captured and either outputted to a text description (scene script) or a simple model with decent normals (SpaRP)

Humans don't really keep complex dense reconstructions in our head. Its all about spatial relationships of landmarks.