The arXiv preprint introduces Targeted Detectability Range (TDR) to fold sky localization, inclination, and mass priors from electromagnetic or neutrino messengers directly into compact-binary detectability estimates, moving beyond the averaged-parameter standard range used in LIGO-Virgo-KAGRA alerts. Applied to every gamma-ray burst recorded in observing runs O1–O3, the method yields tighter horizons than blind searches and is validated against the 90% exclusion distances from modeled targeted pipelines; the study remains a preprint and has not yet undergone peer review. This approach reveals what routine coverage often misses: standard range calculations systematically under-weight face-on or well-localized events, leading facilities to allocate follow-up resources inefficiently when neutrino or GRB triggers arrive. Cross-referencing with the GW170817 multi-messenger campaign (Abbott et al., ApJL 2017) and IceCube’s realtime neutrino-GW coincidence framework (Aartsen et al., 2020) shows that TDR-style priors could have shortened the latency between GW candidate generation and electromagnetic tiling by tens of minutes. The work therefore reframes detector scheduling away from uniform sky coverage toward messenger-informed depth, a shift that will matter once next-generation facilities such as IceCube-Gen2 and the Vera C. Rubin Observatory come online together.