Similar to Fig. 9 but showing different 2D GP analyses tested. As error bars do not convey the correlations between the data points, it is difficult to see that the 600B fit with no mean radius prior – which appears to have much larger uncertainties – actually has a similar constraint on the slope and Na feature compared to the other methods. For the direct retrieval of atmospheric parameters from the data, a dotted line is included that shows the best-fit atmospheric model (as the transmission spectrum is not directly retrieved with this method).