Dear Matt, Firstly, I must congratulate you for your effort in making Larch such a nice, user-friendly, intuitive tool for XAS analysis. Cheers to you and all the collaborators. And thank you for making it available for the whole community. I would like just to report a (small) issue concerning saving Feffit results using Larix. After an EXAFS fitting, I tried successfully save the graphs in every option available, i.e., k-weighted chi(k), chi(R), Real[Chi(R)] and Filtered X(k). Everything works pretty well, except the last one, where an error can be observed on the prompt: File "C:\...\Python\Python311\site-packages\larch\wxxas\feffit_panel.py", line 2211, in onSaveFit ydata = getattr(ds0.data, yname)[:nx] * xarr**kw ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~ ValueError: operands could not be broadcast together with shapes (259,) (326,)" I do not know if it happens just on my version and I know it is a minor issue, since having the window used on back-FT we can plot it easily. In any case, I am just reporting the situation for your knowledge. Cheers, Danilo OLIVEIRA DE SOUZA