From the scope of developing a portable sensor for absolute gravimetry, superior to current devices and enabled by atom-chip based Bose-Einstein Condensate (BEC) interferometry, we derive the central questions:

- How can we further compactify an atom-chip based gravimeter?
- Is a single beam chip Magneto-Optical Trap (MOT) compatible with fast BEC generation and interferometry?
- Does the compact package provide competitive performance? Answering these questions is critical for advancing the field towards a portable, highly compact atom-chip gravimeter.

After demonstration of an interferometer topology enabling significant miniaturisation, the quest to shrink the peripherals remains. Combining the features of a single-beam 3D-MOT with BEC generation and interferometry capabilities to a single-beam atom chip would be a substantial progress. Joining grating elements for the MOT with a high quality mirror for interferometry necessitates effort to avoid compromises on the functionality of either element. A success would imply fewer optical fibres from the laser system to the sensor head. This implies a reduced complexity of the optical bench and fibre distribution system, and consequently an improved robustness, simplicity, as well as compactness. Several viewports could be omitted, simplifying the vacuum system and lifting size restrictions.