We will now discuss some general considerations from our experiences. Magnetisation decays are a time-based measurement, and a distribution of relaxation rates will result in a decay curve that changes shape with elapsing time, so any relaxation not captured in the experiment will skew the extracted τ * and β parameters. This gives an upper bound on the measureable distribution at τ -1 ∼ 0.1 s -1 , and will generally occur at higher temperatures where the fast-relaxing components have already equilibrated before the first measured point. This bias towards long-timescales is not an issue for waveform measurements, as the presence of faster rates can be inferred by fitting the frequency dependence of the oscillating magnetisation. Thus, even when using e ⟨ln [τ]⟩ , a discrepancy may arise with τ Debye waveform rates, and the decay-based rates may not be reliable. It may also occur that the distribution of rates in a sample is significantly skewed, and the waveform data are not well represented by a symmetric Generalised Debye distribution: one alternative is to use the Havriliak-Negami model which also has a known expectation value and variance. For compounds that are required to be modelled like this then we expect that e ⟨ln [τ]⟩ will provide the best measure to compare relaxation times in both cases.