<p>Coherent elastic neutrino–nucleus scattering (CEvNS) provides a sensitive probe of neutrino interactions at low momentum transfer, but its experimental observation is strongly constrained by detector-related effects such as energy threshold, resolution, electronics noise, trigger response, and event-selection criteria. In this work, we perform a detector-response benchmark assessment of CEvNS nuclear recoil observability for alternative target nuclei, with particular emphasis on how a common detector-response model reshapes the measurable recoil spectra. Using Geant4-based simulations, CEvNS interactions are modeled for boron, magnesium, titanium, and zirconium targets under identical neutrino source, geometry, response, and selection assumptions. The generated nuclear recoil distributions are propagated through a parametric detector-response chain incorporating quenching, energy-resolution smearing, noise-induced fluctuations, measured-energy threshold selection, trigger response, and veto rejection. We present a systematic comparison of normalized true recoil-energy spectra, measured recoil-energy spectra after detector response, target-by-target true-to-measured spectral distortions, combined response-level acceptance, and threshold-dependent acceptance variations. The results show that detector-response effects significantly modify the observable CEvNS signal, particularly in the near-threshold region where the recoil population is most sensitive to smearing, noise, and threshold assumptions. The threshold-variation study demonstrates that lighter targets such as B and Mg retain comparatively stronger robustness against increasing measured-energy thresholds, whereas heavier targets, especially Zr, are more strongly affected because of their larger low-energy recoil concentration. Rather than providing absolute event-rate predictions or experiment-specific sensitivity projections, this study focuses on relative spectral behavior and response-level target comparison under controlled benchmark assumptions. The results highlight that CEvNS target evaluation cannot rely solely on weak-charge scaling or generator-level recoil spectra; detector threshold, resolution, noise, trigger response, and veto selection must also be considered. The presented framework provides a consistent methodology for comparing prospective CEvNS target materials at the detector-response level and can be extended in future work to include experiment-specific flux models, backgrounds, exposures, and detector technologies.</p>