We have a tool for enabling/disabling/altering certain things during interactive rendering and it was requested that I add the ability to change Image Upscaling Factor of IOR.
I tried “showproperties renderers.current” but couldn’t see anything in the list that would be relevant.
Unfortunately, it seems this is not accessible via maxscript. System settings are written to a file at C:\Users\username\AppData\Local\Autodesk\3dsMax\20xx - 64bit\ENU\en-US\plugcfg\corona\SystemSettings-xxx.conf