According to the manual, for setstyleext
fontsize, styleproperty, fontcolor and fontratio will take a value of -1 to mean that no change from the base style is required. This works for all the parameters except fontratio.

Setting fontratio to -1 produces the correct display in the designer, but in print preview and output via Image the text squashed to what looks like a font ratio of -1.

I tested and found that the documentation doesn't match the behavior, I will report it.

Thank you.