If it’s an ‘affordable’ 50/1.4 or 85/1.8, don’t hold your breath on longitudinal CA. Granted that the aperture is f/1.2, but the RF 50/1.2 isn’t really all that ‘affordable’ and has ample LoCA as Bryan/TDP’s test jewelry shows.
Sorry for jewelry for LoCA is BS (no offense). One can see things like that with the naked eye since a gem acts itself like a lens (uncorrected). For a proper LoCA test one needs to not have additional “optical elements” in the frame.
Most accounts of the 50 f1.2 points to well controlled LoCA.
Anyway... the 55 sonar is a spectacular lens and came out at €1k and it showed some CA. I am sure that you can find examples of all lenses exhibiting LoCA with jewelry.