ORBIS delivers cloud-optimised GeoTIFF for raster, GeoParquet or GeoPackage for vector, and a STAC item for every asset. There is no proprietary container format.
If you are pulling data through the ATLAS API and processing it in the cloud, use COG and range requests — you rarely need the whole file.
If you are loading into a desktop GIS, GeoPackage is usually the least painful. Esri File Geodatabase export is available for GRIDSCAN defect layers specifically.