Charlesdevoyer using your aivascope with the fx9 is not different from other cameras, as long as you use a monitor that can accuratly display the intended aspect ratio and desqueeze the scope with the right 1.75X ratio you are fine. Only think like on many cameras with no 4:3 sensor is that you will most likely have to crop the sides in post, and loose some resolution which might enhance noise patterns, but most modern cameras have such high resolution that cropping shouldnt be a too big isssue to bother with. Small hd monitors have great desqueeze and framing options, but the latest low cost portkeys monitors also have such features!
The fd ssc lenses can do great with anamorhpc lenses, but most lilely you dont want to shoot below f2.0 or 2.8 and these lenses dont feature many aperture blades so you might get some’ blocky’ bokeh instead of the hard sought after ovals. But my advice is always to work with you have and take it from there.