\delta \! P_{t}} > \omega_\mathit{eff}$ for CRESST detectors (since they purposely bias to minimize electro-thermal feedback), then we can deduce that the new CRESST composite has a signal/sensor bandwidth suppression factor that is $>$10$\times$. In fact, using our 2D simulation, we estimate that this bandwidth-limited energy impulse into the TES, $\sigma_{E_{t}}(\omega_{nt} \! =\! \mathrm{50\,Hz})$, would have a resolution of 5 eV, 10$\times$ worse than the Dirac-Delta sensitivity.

In summary, our first and most important very low-temperature detector design objective is that the signal bandwidth must be larger than the sensor bandwidth, a design goal that, to our knowledge, has not been accomplished by any very low-temperature large-mass detector but that is standardly implemented in 100 mK TES calorimeters for x-ray [@Saab_06_xray] and $\gamma$ [@Irwin_GammaTES] applications. Please note that there is some subtlety in this design rule. CRESST detectors use pulse-shape differences between absorber and TES events to suppress TES chip backgrounds (Fig. \[fig:Traces\_CRESST\_Composite\]); they have both an energy and a discrimination signal with different bandwidths. Thus, the optimal strategy is likely to choose $\omega_{ta} \sim 1/2 \omega_{S/N \, \delta \! P_{t}}$ so that the device discrimination threshold is equal to its energy threshold.

Secondly, if we are able to design 