Active longitudes at high latitudes on inclined stars remain largely unquantified owing to their zero or near-zero temporal variability. The areal coverage fraction of starspots possessing non-standard geometries (i.e. dissimilar from sunspots) may be significantly underestimated. In this talk, I contrast the scalability and fidelity of complementary observational techniques for quantifying starspot areal coverage fractions and temperatures. I demonstrate the limited-albeit-informative constraining power of precision monochromatic lightcurves. I have developed a flexible two-component spectral inference framework to measure starspot area and temperature from composite spectra of spotted stars. The framework provides exceptional constraints on the total starspot coverage of a stellar hemisphere, especially when combined with high-resolution high-bandwidth near infrared spectroscopy, such as IGRINS or iSHELL. I propose a path forward for evaluating starspot-induced biases in star cluster ages, eclipsing binary radii, and exoplanet transit depths.