In this work, Restricted Boltzmann Machines (RBMs) trained with different numbers of iterations were used to provide a large diverse set of energy functions each containing many local valleys (LVs) with different energies, widths, escape barrier heights, etc. They were used to verify the previously reported possibility of using the D-Wave quantum annealer (QA) to find potentially important LVs in the energy functions of Ising spin glasses, Markov Random Fields and related problems that may be missed by classical searches. Instead of the technique of the previous work, similar to the one used in training graphical models with Contrastive Divergence (i.e., initiating the Markov chain from each of the training patterns in the dataset), which is useful for time-efficient sampling in machine learning, this work utilized extensive simulated annealing (SA) with an increasing duration in an attempt to find classically as many LVs as possible regardless of the computational cost. SA was conducted long enough to ensure that the number of SA-found LVs approaches that and eventually significantly exceeds the number of the LVs found by a single call submitted to the D-Wave. Even after a prohibitively long SA search, as many as 30-50% of the D-Wave-found LVs remained not found by the SA. In order to establish if those LVs that are found only by the D-Wave represent potentially important regions of the configuration space, they were compared to those that were found by both techniques with respect to different properties of the corresponding LVs. While the LVs found by the D-Wave but missed by SA predominantly had higher energies and lower escape barriers, there was a significant fraction having intermediate values of the energy and barrier height, even after the longest classical search attempted in this work. With respect to most other important LV parameters, the LVs found only by the D-Wave were distributed in a wide range of the parameters' values. Finally, in an attempt to explain which LVs could not be found easily by the SA, it was established that for large or small, shallow or deep, wide or narrow LVs, the LVs found only by the D-Wave are distinguished by a few-times smaller size of the LV basin of attraction (BoA), which was estimated as the number of higher-energy states sampled above the height of the smallest escape barrier. Apparently, the size of the BoA is not or at least is less important for QA search compared to the classical search, allowing QA to easily find many potentially important (e.g., wide and deep) LVs missed by even prohibitively lengthy classical searches.