In this work, we have used bulk combinatorial synthesis to rapidly identify a (Nd,Ce,La)-Fe-B composition that is both Nd-lean (<50% of total rare earth content) and exhibits good thermal stability (TC~269 °C). Bulk anisotropic magnets of the corresponding composition [i.e. (Nd0.47Ce0.28La0.25)2.2Fe14B1 (at. %) + (1.5wt.% TiC)] were synthesized by hot deformation and hot-roll processes. To enhance the energy product of the hot deformed alloys, feedstock powder with 2.5-7.5wt. % Ce-Al-Cu grain boundary modifier was blended together prior to deformation processing. Moreover, hot deformation processing parameters, temperature (T), and processing time (t), were examined over a wide range to enhance the energy product of the resultant magnet alloys. We found that adding just 2.5wt. % Ce-Al-Cu increased the maximum energy product from ~12 MGOe for the monolithic alloy to ~20 MGOe for the alloy with added grain bounder modifier. The processing parameters (e.g., temperature and time) identified for hot deformation were applied to the hot-rolling process to synthesize samples with larger dimensions that exhibit an energy product of 17.7 MGOe with 5wt. % Ce-Al-Cu added.