We also explored the use of various features in the construction of the LMF. At an early stage, the density Laplacian was abandoned as a feature due to convergence issues observed during subsequent SCF calculations. We conducted detailed evaluations using the EXX energy density as one of the features, which provides a hyper-meta-GGA-type LMF. This did not alter the quality of the LMF notably. However, it may generate some complications for further implementations, e.g., in a TDDFT framework, as the functional becomes non-linearly dependent on the EXX energy density. We therefore decided to currently focus on a typical meta-GGA set of features for the n-LMF. While further, more systematic tests are conceivable and may provide further insights, we are confident to have identified the best selection of activation functions for a stable and effective process.