It works only once at design time, but in run time changing of
RVAControlPanel.DefaultFileName doesn't work, and the file name is still same as set in design time.
Yes, if you need changing file name AFTER its assigning, you can change
rvActionSave1.GetDoc(RichViewEdit1).FileName.
It works both for default file name (assigned by New) and for exact file name (assigned by Open or SaveAs).