geoIntersect queries on spherical geometries are not adapted to our use case. Our need is to retrieve a list of tiles intersecting a given area of interest (AOI) in a flat 2d geometry.
Classical geo-spatial databases (PostGIS and Oracle Spatial) support this kind of approach at no extra cost and we would expect the same from MongoDB.
In MongoDB , using a 2dsphere index forces us to implement a workaround adding an artificial margin to the AOI and making a post-processing to remove false positives. See attached slides for explanations.