I have been asked to add my 2 cents here...
Recall that one typically peaks on an element of interest on a specific spectrometer bearing a specific crystal. Say F Ka on a nominal 45 A 2d diffraction. Thus the software will “automatically” set the spectrometer position, correctly showing the F Ka peak at the “published” position (whether sin theta, mm, A or eV). 2d and K refraction value are essentially non-observable. The point of having a correct 2d with correct K refraction value are that when one wishes to see higher order markers, they will fall in the right place. That is what I found years ago with the SX51 and good old PfW v9 (still running it on SX51).
A test to tell me if this is relevant. With say 60A diffractor, peak on O Ka on an aluminosilicate. Then in PHA mode integral, do a detailed slow wavescan, for whole spectrometer range, and see if the 3rd order higher order peak markers for Al and Si (and maybe other elements too) line up with the observed peaks. If they do, hurrah, and no need to do anything. If they don’t, then 2d and K need some adjustment.
John