Limit the number of ratios plotted in overlay_all_ratio plots/Error when using two ratios in LineRatioFit

[Carl Ferkinhoff]

When using "LineRatioPlot" and "overlay_all_ratio" to make plots like the following

Is there a way to only select some of the ratios to plot? I ask because in this case the Cii/FIR ratio is in my mind degenerate with the (OI+CII)/FIR ratio and I would prefer not to include it in the graph. 

To address this we tried to have the ratios be our measurements (i.e. CII/OI and (OI+CII)/FIR ratio), thinking that then it would only show explicity the ratios we entered as measurements. However, if we do this then attempting to run "LineRatioFit" gives us an error that it needs three measurements so it can make at least two ratios . . . however we've already explicitly defined the two measurements.