By design, printer/plotter choicese are saved in each dwg file in each tab (file creator control): your autocad-variant or viewer program will never auto-replace these on it's own.
The free viewer also does not let you write back to the file, so any changes you make remain temporary. This is also by design.
Does that answer all of your questions?
The free viewer also does not let you write back to the file, so any changes you make remain temporary. This is also by design.
Does that answer all of your questions?