I suggest you run the task with --show config to see what config fields are available. You can specify a glob pattern as well, so this might work even better: --show config="*psf*".
If processFile.py is calling the current ProcessCcdTask then PSF estimation has moved to the subtask CharacterizeImageTask and the field is probably config.charImage.installSimplePsf.fwhm
Yes, thank you. Unfortunately, the new name is apparently not initialPsf so I didn’t find anything either through --show config or through look through the created config/processFile.py in the Butler repo.