Is it necessary to convert valid InverseVariance uncertainties to StdDevUncertainty?

[weaverba137]

In 09b-Specutils/Specutils_analysis.ipynb, an example SDSS spectrum is read. SDSS stores uncertainty as InverseVariance by default, and the SDSS reader is aware of this. However, in the subsequent analysis examples, the uncertainty has to be converted to standard deviation.

• Is it still the case that the analysis functions can only accept StdDevUncertainty?
• If not, can we simplify the notebook by directly using InverseVariance?
• See also Uncertainty documentation does not mention allowed types of uncertainty specutils#1298.