Font size
Steven Brough
You could create a macro that will go through a selected PPTX file and make the changes for you. Open the macro file (excel or powerpoint) click browse, then click run after you select the file.
Edvard Pavliuk
I agree, why not implement it as it is already in the text editing theme, but instead of using scaling factors, specify exactly what the size of certain blocks should be..............?