Effective area for representative cleaning candidates calculated from nominal (full lines) and high NSB simulations (dashed lines). Horizontal dashed lines indicate the energy threshold, defined as the energy at which the effective area is 10% of its maximum. The bottom panel shows the ratio between the nominal and high NSB cases. Both example time-cleaning candidates illustrate extreme cases of overestimating or underestimating the signal efficiency at higher NSB rates; both are discarded according to the set limit.