Yes I had to set the phcPreviewer and I found this out the hard way as it is not really documented. The documentation for the pePreviewStyle only says the following:

Switching the pePreviewStyle dynamically in a program is possible but requires a closer look at the phoPreviewContainer property. The object might need to be deactivated and destroyed.
Once the object is initialized and is displayed the phcPreviewer is never reset. Maybe a better approach would be to have the class know when the private.pePreviewStyle property has changed then it automatically resets the phcPreviewer. Honestly I was really skeptical with touching this particular property because the naming looked like it is a private property that I as the developer should not need to set.