OK, I found this thread:
Alnitak flat man control is not working - Sequence Generator / Equipment Compatibility - Main Sequence Software (sequencegeneratorpro.com)
So it seems that this is the intended behavior - which is different from my older version. If I am understanding this correctly, it is simply no longer possible to take any test images to determine the correct flat panel setting for a given exposure. It also seems that this makes the Flat Box module obsolete.
I would like to use Auto Flats, but my use case doesn’t seem to fit the Auto Flats model. My imaging train stays in the same configuration all the time and I only collect flats a couple of times a year - or if a new dust mote shows up on the sensor. So I am accustomed to setting up the “No FIlter Flats Data” (I use OSC) in the Equipment profile manager for my exposure and flat box settings. Problem is, now where doesn’t seem to be a way for me to experimentally determine the flat box values.
The biggest issue I think I have with Auto Flats (which may be complicate by my ignorance) is that it seems to find the correct exposure length for a given flat box setting. Since I dark-correct my flats, I would like to choose the exposure length (that is already in my dark library) and adjust the flat panel to get the right exposure.
Anyhow, if anyone knows how to take test exposures by varying the light panel settings, please let me know. Otherwise, I’ll muddle through with Auto Flats.