Rp47ics

Fujinon XF23mm f/1,4 and 50mm  f/2
Almost 100% of all needs, Use for wedding and portrait photography 

There are two reasons that minimum ISO is limited to 640 - using DR 400 and using F-LOG for movie

I found the solution: set ISO on A, ISO dial setting (A): command (not auto)

There is a difference between Film Simulation and Custom Profile - changing the Film Simulation doesn't automatically change the Custom Profile.
If you want the different settings for different Film Simulations then set up different Custom Profiles.

Film simulation is just one piece of a Custom Setting. When you select a Custom Setting, you are loading the entire Custom Setting into the camera. All of the many parts of that Custom Setting --- film simulation, white balance, highlight tones, shadow tones, color saturation, noise reduction, sharpening, DR, etc. -- will replace whatever your camera had been set to. When you change the film simulation, that changes just the film simulation, without changing anything else.
You just need to set up a "standard" Custom Setting. It's probably most convenient to put that in C1.