In this contribution we detail the optimisation and benchmarking of new JKFit basis sets for sodium and magnesium, and revisit the JKFit sets for aluminium through argon to ensure robust density fitting when correlation consistent basis sets that include tight-d functions are used. Details of the general computational procedure can be found in Section 2, the design, development and optimisation of the JKFit sets in Section 3, and benchmark calculations on molecular energies, reaction energies, and spectroscopic constants in Section 4.