stars have smaller values of $\Delta {\rm mag_{p}}$, so observing late type stars to the noise floor would result in the detection of planets much smaller than 1 Earth radius; from an exoEarth candidate yield perspective, an SLSO method devotes too much observing time to late type stars.

@2005ApJ...624.1010B explored varying $\Delta {\rm mag}_{\rm obs}$ to maximize the mission yield, but kept $\Delta {\rm mag}_{\rm obs}$ the same for all stars. We refer to this method as a tuned limiting search observation (TLSO) method. Clearly the TLSO method performs better than the SLSO method. However, the TLSO method still fails to take advantage of the dependence of $\Delta {\rm mag_p}$ on stellar type and, requiring many calculations of photometric completeness and exposure time, is computationally inefficient. For typical mission parameters with modest aperture sizes, the TLSO method tunes $\Delta {\rm mag_{obs}} < 26$ such that the noise floor is never reached, but we explicitly required $\Delta {\rm mag_{obs}} \le 26$ when using the TLSO method in this paper.

@2012PASP..124..418T ignores the contribution of the planet’s Poisson noise and adjusts the exposure time for each star to roughly that required to detect an exoEarth at quadrature, effectively scaling $\Delta {\rm mag}_{\rm 