Additional exposure time required in 2035 to maintain 2024 S/N for VLT/FORS2 observations, averaged over zenith angles 0°–60°. The shaded region highlights the critical uncertainty between debris models: faint galaxy observations (27 mag/arcsec²) require either 8% (MASTER, lower curve) or 34% (MASTER/ORDEM-scaled, upper curve) longer exposures, directly impacting survey efficiency and time-domain astronomy capabilities.