We propose to use SANS to measure the magnetic flux line lattice in clean KFe2As2 crystals with the field-direction close to the basal plane. In this configuration, Bc2 in Tesla is more than double Tc in Kelvin, which is a simple version of the condition for Pauli-limiting of superconductivity. We may therefore expect unusual behaviour of the "field-contrast"; of the flux lines, a possible FFLO state or magnetic ordering, similar to that observed in CeCoIn5. However the pairing in KFe2As2 is probably s+-, rather than d-wave, giving a new perspective on the physics. We have observed well-formed flux line lattices in our crystals; previous measurements and detailed consideration of anisotropy effects indicate that the flux lattice structure should be observable for a field applied close to the basal plane.