Klein pairs van der Waals heterostructure fabrication with a cryogenic scanning-probe 'Atomic Single Electron Transistor,' built on a quantum-twisting-microscope platform, to directly image sub-moire electrostatic potential landscapes with ultrasensitive, high-spatial-resolution electrometry. This is an unpreferred/borderline quantum-sensing inclusion: the sensor is an SET-based electrometer rather than an NV-ensemble magnetometer (which reaches pT/sqrt(Hz) via DEER/NMR/T1 protocols), but it shares the goal of pushing single-defect-level sensitivity for imaging quantum materials.